PEDRO PULLS THROUGH!

Chapter One
The Night of the Thirteenth
The night was hot and sultry, without a faint breath of wind. There was thunder in the air, but now it was the hush before the storm, still with that deathly silence that makes men start at little sounds.
James Craddock stood by the long window of his bed-room and stared out into the night.
"Another year," he muttered, and a faint, mirthless smile appeared on his dark, thin face, with the baleful eyes. Some men had said that James Craddock had the face of a devil. "Another year gone. Again it has come round. Again it is the night of the thirteenth."
The night of the thirteenth. There was something in that thought to twist his lips weirdly in that dreadful, mirthless smile.
He was a bent, misshapen figure there in the gloom. A middle-aged man was James Craddock, with long arms and claw-like hands and almost a hump upon his back. A thin dressing-gown was wrapped loosely around him, and old leather slippers were upon his feet. Behind him the luxuriously furnished bed-room was in darkness like that of a tomb, but outside the starlight alone shone faintly over the garden and the trees at the cliff-edge and on the sea beyond.
Not a breath of wind. The trees were motionless — a row of sombre fir-trees. The sea was like a pond, smooth as glass, black as jet, not one ripple to catch the starlight. James Craddock's eyes wandered over the scene.
"It's hot," he told himself, and wiped the perspiration from his brow with a skinny hand. "I sha'n't sleep well to-night, not in this heat."
He stared up at the sky. A heavy bank of inky clouds was lying away to the west, drifting slowly towards the house on the cliffs, the fringe of the coming storm. Somewhere round the corner of the house a dog yawned. James Craddock could hear the snap of its teeth as it closed its mouth afterwards. Again the grin came upon his face.
"But the brute won't sleep to-night," he muttered. "It will be on watch."
His glittering eyes roamed over the dusky lawns. His bed-room was on the ground floor. That was an eccentricity of his. He hated upper rooms. Long years spent in African bungalows were the cause of this perhaps. He glanced again at the sky, where that bank of sinister cloud was rifting up over the stars, glanced again out to sea, where the water lay so still, stared for a moment or two at the dark outline of the house on the headland, over a mile away, high on the cliffs above the sea, as was his own house. He thought of Steinruck, the man who lived there — a man he did not like. Then his thoughts returned to that other thing which seemed to be obsessing him.
"The night of the thirteenth!" He turned away from the window abruptly, with a cackle of dry laughter. "Well, well! The dead can't return from the grave. McQuay swore to kill me on the night of the thirteenth, the poor fool, but he died himself on that night. Well, well!"
There was a tap at the door.
"Come in!" cried James Craddock. And his young secretary, Hamilton, entered.
"You rang?" asked the young man.
"I did," snapped Craddock. "You've been a long time coming. I want you to take that confounded calendar away." "The calendar?" echoed the young man in surprise.
"Yes, the calendar," snapped his employer. "Take it away! Don't stand there looking like a fool!"
Hamilton groped his way across to where the calendar hung upon the wall. The big number 13 could be seen dimly, heavily black on the white paper. He took it from the wall.
"Anything else, sir?"
"Nothing. Get out!"
Hamilton's lips pursed, and his eyes gleamed for a moment. Used as he was to James Craddock's ways, however, he left the room without answering. The door clicked softly behind him.
"Glad that's gone!" muttered James Craddock, as he threw off his dressing-gown and climbed into bed. "That great black figure 13 was horrible!"
Suddenly he shuddered.
He could not sleep. He lay staring through the gloom, watching the stars go out one by one as the pall of cloud slid over the sky. The silence was broken now. A faint breath of hot air stirred in the garden, bringing with it a far-off mutter of thunder.
"It's hot!" he told himself for the tenth time. "Like Africa, almost. Like — like that night when young McQuay died and swore that — that — " He broke off, licking his dry lips. "But McQuay's dead," he told himself, staring round in the dark. "Dead! And I helped bury him! The dead can't rise from the grave, not even when — "
A faint sound in the garden caused him to start and tremble. A cold perspiration stood out on his brow. Then he grinned that dreadful, mirthless smile.
"You're all nerves!" he told himself impatiently. "Pull yourself together!"
But he was staring at the window now. And the perspiration crept out again on his brow. What was that which he had heard? A dull, soft thud, thud, thud. Someone crossing the lawn? Someone coming through the dark, coming to his room? Ah, what was that? What was that?
His eyes were wide, showing the white all round the staring pupils. He had half raised himself on one elbow, head turned to the window. Thud, thud, thud, soft and steady across the lawn. He was sure of it. A heavy footstep on the gravel.
Then came the crash of thunder, rumbling and echoing across the heavens, drowning the terrible choking cry that was torn from the very terror-stricken heart of James Craddock as he saw a moving shape at the window.

It was Woodburn, the footman, come to his master's room with his early tea, who found James Craddock lying dead on the floor, strangled. He was only a young footman, and the sight was too much for him. He fainted and when he recovered there were other people in the room — Hamilton, Raines, the other footman, and Briggs, the butler. They told him it had been his scream that had brought them to the spot. Woodburn did not even remember that he had screamed.
There seemed to have been a terrible struggle in that room. The curtains of the bed were torn down, a chair was broken, most of the bedclothes were on the floor. But, as Hamilton remarked — he seemed very cool — the great storm in the night would have drowned all sound of it.
It did not take long for the local police, hastily summoned by telephone, to reach the house, lonely though it was, and four miles from the village. But the local police wanted further help, and by evening Scotland Yard was on the scene.
Detective-Inspector Martin, of the C.I.D., soon found things that bewildered him utterly at Seaview House, the house where James Craddock had died on the night of the thirteenth. There were marks on the lawn, for instance, deep marks that at first he had taken for footprints, but which were like no human footprints that Martin had ever seen.
And to the local inspector he said, with a grunt: "This is a case for Blake. I'll try to get him down."
He went to the telephone, got a trunk-call through to London, and was soon in eager conversation with someone at the other end of the hundred-mile wire. It was clear to the local man that this was none other than Sexton Blake, the famous detective of Baker Street.
At last Martin hung up the receiver. He turned to the local man with a grim smile on his bulldog-like face.
"That's all right, then," he said gruffly. "Blake'll be down here to-night."

Chapter Two
The Strange Footprints
"So this is the place, guv'nor!"
It was Tinker, the cheery young assistant of Sexton Blake, who made the remark, as he stared up the long drive at the ugly brick pile ahead — Seaview House.
The Grey Panther had done the trip from town in fast time, with Tinker at the wheel. Less than three hours for the hundred miles! It was ten o'clock then, with a bright moon flooding Seaview House with silvery light, as the powerful car sped smoothly up the drive.
Blake was seated next to Tinker, whilst in the back seat was the form of a huge dog. This was Pedro the bloodhound, whose scent-trailing powers had proved invaluable to Blake on many an occasion.
The car slowed down by the front door, and as they jumped out onto the gravel, Martin came hurrying out of the house. He had heard the car's engine in the drive.
"Glad you were able to come," was his greeting. "This is a black mystery, if you like. Come inside."
They entered the spacious hall, crossed it, and passed through a high doorway into the dining-room. At Martin's request an appetising cold supper had been made ready for Blake's and Tinker's arrival, and the long drive had sharpened their appetites so that they tackled the meal with gusto.
Pedro lay stretched by the table, watching Blake with his great brown eyes. While they ate Martin ran over the case.
"James Craddock was killed during the great storm that they had here last night," he said. "There was a struggle, clearly, as you will see for yourself when you have a look at the room. As far as I can see, the man who entered his room and killed him left no clue to his identity in the room itself — if it was a man."
"Do you suggest that it was a woman?" asked Blake.
"No." Martin shook his head. He leaned forward, and pursed his lips. "If it was a man — and not some kind of monster out of a nightmare."
"Monster out of a nightmare, eh?" echoed Tinker, staring hard at Martin. "My hat, Inspector, you're getting a bit fanciful in your old age, aren't you?"
"Wait!" said Martin. "Wait till you've seen those footprints on the lawn."
"What are they like?" queried Blake.
"I can't explain — weird, huge things. But you'll see 'em! They seem to be all that the mysterious killer has left, though. There's a gap in the hedge close by the cliffs, as if someone or something had broken through, too, by the way. A dog that James Craddock always had roaming the gardens at night was found dead, terribly mutilated, close by this gap in the hedge. Nothing has been stolen. And that's all there is to it, so far."
Blake, his meal finished, leaned back in his chair and lit a pipe. He was frowning thoughtfully.
"I think I'll have a look at these footprints of yours first of all, before I look at the room," he murmered; and, followed by Tinker and Pedro, Blake returned with Martin to the hall, passed out of the front door, and crossed the gravel to the moonlit lawn.
"Here we are!" muttered Martin. "What do you make of that, eh?"
He had halted by a deep mark in the soft grass. Several feet away was another, and beyond that a third — a whole trail of them, in fact, leading away across the lawn to the stretch of woodland that flanked the drive.
"My only hat!" breathed Tinker.
He could understand now Martin's odd remark about a monster from a nightmare.
It certainly did not seem to be a human footprint. If a man had made it, he was wearing some strange things upon his feet, at any rate. Almost square, the clean-cut depression in the grass seemed to show the marks of immense toes, but there was no instep — the whole footprint, to call it that, was flat from heel to toe.
"By Jove, that's strange!" muttered Blake; and Tinker had seldom seen him aroused to such intense interest in so short a time.
The detective took from his pocket a powerful electric torch, and went down on his knees, examining the strange mark intently with the aid of the powerful light. He rose to his feet at last and shook his head.
"I confess I can make nothing of it yet," he murmured. He took a long pace to the next similar mark. "And what a stride! It must have been a huge man to make a stride such as this."
"Come and have a sniff at it, Pedro, old chap," said Tinker.
But though he took the bloodhound right up to one of the imprints, the dog took no notice of it.
"That's queer!" grunted Martin. "That dog of yours is generally mighty hot on any scent, I've noticed."
"It is queer," agreed Blake. "Let's follow these marks."
Across the dark lawns they followed the trail of heavy imprints, and into the shadow of the trees. Here it was necessary to bring the torch into play again, but by the vivid light it was easy enough to continue on the trail.
They followed the marks through the grassy paths and clumps of undergrowth. Torn bushes showed where someone had apparently tramped through them regardless of thorns and brambles. There were two trails, one going and one coming. At last they came to the hedge that bordered the road at the edge of the Seaview House grounds, and here they found the gap of which Martin had told them. Evidentally it was a gap that had only recently been made.
"And beyond?" asked Blake suddenly.
"No good," said Martin. "There's nothing to be seen on the road — not a thing! The rain last night swept all trace away, if there was anything left in the dust. And, of course, the road surface is too hard for any imprint."
"Pedro ought to be able to follow it, all the same, despite the rain, if only he'd take some interest in those marks," put in Tinker, with a puzzled air. "But he doesn't care a dog-biscuit about 'em — won't look at 'em. Odd, isn't it?"
"Very," agreed Blake. "Even so, Martin, I mean to have a very keen search for further footprints like this, if one can call them footprints. There'll be mud patches somewhere on the road, I suppose, and we might find something in them."
He turned.
"And now to have a look at the room itself!" he exclaimed; and the three made for the house again, with Pedro striding beside them.
Tinker glanced down at the huge hound in mock reproval.
"First time I've known you to be a wash-out, old chap," he said, letting a hand fall on the dog's head.
But, after examining the ground-floor room, where James Craddock had died, Blake had to agree with Martin that there was nothing there in way of a clue, unless a certain mark on the wallpaper constituted one.
If it did, it was a vague clue at the best, since it was beyond even Blake's powers to fathom its meaning at that early stage in the proceedings. The mark consisted of five scratches in the wallpaper by the bed, rather as though some animal had clawed the wall.
They turned in for the night soon afterwards, for it was necessary to wait for daylight before they could carry on with their investigations. As he lay awaiting sleep in the dark room next to that occupied by Blake, Tinker's brain was very active.
"Well, I dunno!" he mumbled to himself at last; and the sudden sound of the youngster's voice in the silence caused Pedro, stretched at the foot of the bed on the carpet, to raise his head for a moment. "I dunno! Even the guv'nor seems really puzzled for once! What on earth left those marks on the lawn — and p'r'aps that mark on the wallpaper, too? Man, or beast, or what?"
When Tinker finally fell asleep it was to dream of horrible nightmare monsters — gorillas, and things half human and half gorilla, and other things that never walked this earth except in the imagination of a nightmare.
In fact, Tinker was thoroughly glad to find himself awake again, with the morning sun streaming into the room and with Blake standing at his bedside.
"Shake a leg, young 'un!" exclaimed Blake. "We are going to gobble down a bit of breakfast, then set out on the trail of those weird footmarks to see if we can't track 'em down to their lair!"
And, with that promise, Tinker needed no second bidding. To track those weird footsteps to their lair! That would be a thrill indeed, if they could only manage it!

Chapter Three
On the Trail
"Well, here we are at the gap," said Detective-Inspector Martin.
He did not speak very enthusiastically. He himself had searched the road beyond for a considerable distance, and the ground beyond that without finding any further trace of the mysterious marks that had appeared upon the lawn of Seaview House on the night of the thirteenth.
"Come on, then!" ordered Blake, and pushed through the gap. Tinker followed, then Pedro slipped through. Lastly came Martin.
"I propose we split up, Tinker, you and I," said Blake. "You take the cliffs, I'll take the woods. If we search in ever-increasing circles we ought to find something, surely."
Martin grinned.
"I've tried and failed," he observed. "It'll be interesting watching you to looking for what isn't there!"
He seated himself on a stile across the road, pulled out a cigar from his waist-coat pocket, and lit it.
"Whew!" gasped Tinker, holding his nose. "Where did you get that roll of brown paper, inspector? Paper-basket at Scotland Yard?"
He ducked, as Martin aimed a good-humoured smack at his head, which missed its mark.
Tinker had to admit, after he and Blake had been searching for nearly two hours, covering large tracts of ground on either side of the cliff-road, that it looked as though the C.I.D. man's confidence that their search would be fruitless was justified.
And yet in his heart Tinker felt that those strange imprints in the earth could not have landed on the ground out of thin air! They clearly came from the road — and so, as Blake argued, at some point they must have entered by way of the road. If only they could find that point!
And then, when Tinker had all but given up hope, he gave a quick exclamation!
There, on a patch of sand at his feet, was just such an imprint as they were looking for!
Carefully marking the spot, he went in search of Sexton Blake.
Tinker had found the imprint at a point over a quarter of a mile from the gap in the hedge by which the mysterious unknown had entered the gardens of Seaview House. Blake, meanwhile, had gone far off in the other direction in pursuit of the search, and it was a while before Tinker found him. But some time later Blake, Pedro, and Detective-Inspector Martin were back with Tinker at the spot where the imprint showed in the sand.
Martin looked rather chagrined. Blake's eyes were gleaming in a quietly confident way.
"Good!" he murmured. "Nothing like patience, is there, inspector?"
"Rub it in!" said Martin, with a rueful grin, and Blake and Tinker laughed.
"This seems to be the spot where the man or creature, or whatever it was that left these imprints, got on the road on its way to Seaview House that night," went on Blake. "For a quarter of a mile it must have come striding along the road through the dark, unseen by mortal eye, on its dreadful mission of death! What was it? What's the riddle we have to solve — and it's a question that may have a strange answer."
"You're right," growled Martin. "Thundering strange!"
"But if we can only track down these footmarks we ought to be able to answer it before long," continued Blake. As he spoke he was moving slowly off towards the cliff-edge. "Here are more of these footmarks."
Yard by yard they trailed the mysterious marks in the sandy soil. Through the bracken they led, right to the cliff-edge. A steep path led down to the broad golden sands below at that point.
"It came up this path, whatever it was," muttered Tinker.
"So down we go!" replied Blake cheerfully, and a little later they were on the sands.
But here they met with disappointment. The sea at high-tide washed nearly to the foot of the cliffs, so that the trail of imprints had been obliterated by the tide long ago.
"We're dashed!" cried Martin. "Hang it! Did the thing come out of the sea, or what?"
Blake was staring round keenly at the stretch of smooth sand that curved away along the foot of the headland. His eyes lifted to the bleak house that rose squat against the sky at the end of the rocky promontory.
"What's that place?" he asked suddenly.
"That?" echoed Martin. "Oh, a man named Steinruck lives there — Professor Steinruck. The butler at Seaview House told me that. Steinruck was an acquaintance of Craddock's."
Blake nodded thoughtfully, staring away at the house on the headland. Slowly he took from his pocket his curved briar pipe, filled it and lit it.
"I think we might do well to pay Professor Steinruck a visit, Tinker," he said suddenly. "Yes, I feel sure we ought to do that."
"Now, guv'nor?"
"Oh no. Tonight, when it's dark. Yes, later tonight!"
Martin glanced at him sharply.
"Do you suspect Steinruck of having something to do with this?" he asked.
And Blake smiled and shrugged his broad shoulders without replying to the question.
"I'll tell you what we will do now, Tinker," he said. "We'll paddle! Would you like a nice paddle along the edge of the sea, Martin? They say it strengthens the ankles."
"Look here, what are you getting at?" exclaimed Martin.
Sexton Blake was already removing his shoes and socks and rolling up his trousers-legs. He smiled at Martin's puzzled face.
"Candidly," he said, "I want to get along to the headland, for the purpose of seeing if there is a cliff-path leading down from that house on to the sand. I suspect there probably is. But I do not want to appear noticeable to anyone who may see us from the house. If we paddle along to the headland, however, it will appear that the pursuit of simple pleasure has led us there. Besides," he added, chaffingly, "I am anxious to see what a detective-inspector of the C.I.D. looks like paddling! I should say it's not a common sight — eh, Tinker?"
Martin chuckled.
"P'r'aps not," he admitted. "But I shall enjoy it, I can tell you! Hang it, I've not paddled for years! Here goes!"
And two minutes later the paddle was in full swing! The three, with Pedro splashing joyously after them, looked like three innocent holiday-makers as they strolled through the shallows, carrying their boots and shoes.
But underneath it all was a grim purpose. And when they reached the spot under the cliffs where Steinruck's house was perched, and Blake saw that there was a winding cliff-path from the summit down to the sands, he nodded.
"Thought so," he murmered. "Yes, to-night we'll pay Professor Steinruck a visit! And I'll tell you this, Martin — I advise you to bring your Browning automatic with you!"

Chapter Four
In the Sea Cavern
"This certainly wasn't on the programme," murmered Blake coolly.
They could see nothing of the man on the roof. He was utterly invisible in the wall of darkness that lay behind the dazzling beam of the searchlight. But that it was Steinruck none of them doubted.
"Stay where you are," went on the steely voice, "and raise your hands above your head. If you don't obey, I shoot. I'm a good shot; I sha'n't miss."
There was no choice for them but to obey. To have resisted the command would have been sheer suicide.
A moment later they heard a strange hissing, sizzling noise from the direction of the roof.
"What's that?" muttered Tinker.
There in the light of the dazzling beam they waited, hands raised. There was no use in attempting to run off into the darkness. They knew that the searchlight would have swung after them, picked them out, and that would mean the man on the roof — Steinruck, as they believed him to be — would shoot them down as they ran.
The strange hissing noise continued. Suddenly a rolling cloud, like smoke, drifted into the ray of the searchlight. A few moments later Tinker scented a pungent smell that filled his nostrils and throat in a moment, making him cough and choke helplessly.
He heard a low whine from Pedro. The dog was standing by them; it would never desert Sexton Blake and Tinker. But clearly the plucky creature was being stifled by the pungent fumes that were then drifting round them, white and ghostly.
Blake tried to tell the dog to leave them. But before he finished the words the detective reeled, a hand to his throat. Then he staggered to his knees, toppled on to his side, and lay still. The others crumpled up beside him, and the dog, too.
There in the light of the relentless ray, the white smoke hazy around them, the three crumpled human figures lay heaped, the senseless dog at their side. There was a laugh from the darkness of the roof, and abruptly the searchlight was switched off.

When Tinker opened his eyes it was with a splitting headache throbbing behind his brow. He raised his head, staring about him. He saw the sea very close at hand, bashing over half-submerged rocks. Then he realised that he was tied down, lashed to one of those rocks himself with the waves creaming at his feet. Above him arched the dark roof of a cavern.
"My heavens!" he muttered, and his mouth felt suddenly dry.
"Tinker!"
It was Blake's voice. The youngster twisted his head and saw in the gloom that Blake was lashed to the next rock, whilst Martin was spreadeagled upon the rock beyond, also tied down with stout cords and helpless.
"Guv'nor, we — we — "
"This is Steinruck's work," broke in Blake. His voice was steady but coldly grim. "He's a human fiend. He's tied us down, with the tide rising. The sea lies five feet deep over these rooks at full tide."
"And the tide's coming in?" breathed Tinker.
"Yes."
There was a long silence, broken by the mutter of the waves as they lapped round the rocks under them. The water seemed to be rising quite swiftly. A wave came and drenched Tinker's feet.
He strained against the cords that bound his feet and arms, hoping that by dragging upon them he might manage to sever them on some sharp corner of the rock. But though he strained till it was an agony, they held firm, and he knew that the attempt was useless.
There was a sudden long-drawn sigh from Martin. He had only just recovered his senses.
As the realisation of his position came to him the C.I.D. man cried out thickly.
"Yes, this looks like the end," answered Blake calmly. "Still, you never know your luck. Whilst there's life there's hope! That beastly smoky stuff was some kind of poison gas, of course, and it sent us all to sleep. That hissing noise was the sound of its being discharged from some sort of a nozzle."
"Wonder what's happened to Pedro?" muttered Tinker.
The sea had risen considerably higher by then. Each wave washed over his feet, splashed up his legs. His teeth began to chatter with the cold.
"Perhaps someone will come along," he cried rather wildly. "I'll shout."
He sent a ringing cry echoing over the rocks. Blake said nothing, but in his heart the detective knew that Steinruck would not have left them ungagged had there been a chance of their being heard. They had been left tied to the rocks in a long, natural cavern, deep under the cliffs — Blake had realised that fact from the first. Tinker's cry echoed eerily about them, but would scarcely penetrate into the open. Even if it had, there was not the faintest chance of anyone passing that way at that lonely point on the coast, especially at such an hour.
Tinker was tied to a lower rock than the others, and the water had reached him first. He would be the first to drown.
An extra heavy wave, splashing and foaming down the long cavern, lifted high around him, soaking him to the waist. He gasped at the terrible coldness of it. And then he gave another gasp.
"Guv'nor, did you hear that?"
It was a scrambling noise somewhere among the dry rocks behind them. Something was climbing out to them! They heard a heavy splash as it plunged into the water and swam. Then again the scrambling sound. The person, or thing, had scrambled up on to the group of rocks to which they were tied.
It was then very near them, and suddenly Tinker caught his breath.
Was this the mysterious Thing? The nightmare creature which Martin had pictured as having left the strange footprints?
He felt a sudden, hot breath upon his face.

Chapter Five
Steinruck's Invention
"Pedro!" cried Tinker!
It was the great bloodhound.
It was clear in a moment to both Tinker and Sexton Blake that Pedro had somehow escaped from Steinruck, after regaining his senses, and had found them.
The huge brute was dripping with water. He whined unhappily, clearly realising that things were badly wrong. Blake laughed bitterly.
"You can't help us now, old chap," he muttered.
But that was where Blake was wrong! As if in answer, the dog lowered its muzzle, sniffing at the cords that bound Tinker. Pedro was standing astride him on the wave-washed rock. And the bloodhound seemed to understand!
He had seen men bound with cords too often to fail to realise what that meant. And then he began to bite and tear savagely at the cords that rendered Tinker helpless!
"Go on, old boy! Go to it!" enthused the youngster hoarsely. Hope had come to them, when all hope seemed to have gone!
It all rested on Pedro! And he did not fail them. His great teeth had the cords in shreds in a couple of minutes, and Tinker was free!
Only just in time! The waves were washing higher, clean over the rock to which he had been bound, as he climbed swiftly on to the next rock and began to unfasten Sexton Blake and Detective-Inspector Martin.
"And now for Steinruck!" ground the C.I.D. man fiercely. He twisted his cramped limbs painfully, then felt in his pocket. But the Browning pistol was no longer there. "We're unarmed, but, by heavens, I'll get Steinruck with my naked hands!"
Through the darkness they climbed back over the half-submerged rocks. At one point they had to swim for it. But at last they were on the shingle at the back of the long cave, and it did not take them long to find the natural fissure in the rock by which Pedro had entered. They climbed up out of it, to find themselves in a deep gully, with sloping, grassy sides.
At the top of the gully they found themselves only five hundred yards from Steinruck's house, and they made for it with faces grim and stern.
It was twenty minutes later that the three, together with Pedro, were lying on their faces outside a tall french window at the side of the house. The curtains fell short, and they could peer in under them. At the farther side of the room, a big, black-bearded man — clearly Steinruck — was seated at a table, his long, delicate fingers busy with a strange instrument.
It looked rather like a "wireless receiving-set gone mad," as Tinker afterwards phrased it. Batteries and coils, switches and dials, were spread over the table, connected with one another by yards of snaking wires. Whilst on a short tripod immediately in front of Steinruck's face was an instrument that looked something like a camera with two lenses. Into these lenses Steinruck would peer every now and again.
There was a rifle leaning against the wall not far from the window, and Blake had made up his mind to get it. He quietly whispered his plans to the others, and at a muttered word from him they acted in unison.
Tinker smashed at the window with a spade that he had found in the garden, making a wide gap in two or three busy seconds. Through this gap in the glass darted Blake, with Martin at his heels. They swept aside the curtain, and Blake leaped for the rifle.
He reached it a fraction of a second before Steinruck. But Martin was on to Steinruck as the two fought for possession. With a stinging upper-cut, the C.I.D. man sent the Professor reeling back into his strange instrument.
There was a crash as the bearded man sprawled backwards over the table. Then a crackling electric spark flashed along the wires, there was a sharp explosion, and most of the apparatus was wrecked in a moment.
"Hands up!" commanded Blake, and Steinruck, white-faced, jerked up his arms before the menace of the levelled rifle.
His eyes seemed to be starting from his head with terror and amaze at seeing them, the men he had left to drown in the cave. Then suddenly another look came into his face.
"Hark!" he breathed.
From outside the window came a heavy thud, thud, thud, approaching slowly, steadily across the dark lawn. Steiner seemed to choke, and his face went grey as ashes.
"It's coming this way!" he shrieked. "And I can't control it now! My heavens, it's coming this way!"
He seemed to forget all about the rifle in his panic. With wild eyes he rushed to the broken window and darted through, vanishing into the gardens. Blake did not fire. There was something in the genuine terror shown in Steinruck's eyes at the sound of that thud, thud, thud over the lawn that held his hand.
They raced out into the garden after Steiner. And there they saw what James Craddock had seen at his window on the night of the thirteenth.
A gigantic thing, half-human at first glance, a monster with glassy, glittering eyes, a monster of steel and brass! Its mighty metal limbs moved with an almost human movement as it went striding through the gloom, eyes gazing blindly before it.
They understood all then.
That was the Thing that had left the strange footprints. A mechanical monster, the child of the professor's mad genius, a human-machine, controlled by the apparatus at which Steinruck had been seated. Doubtless by some means of wireless-vision, the lenses on the tripod gave Steineruck a view of what was seen through the Thing's glaring "eyes" as it moved to his control. Arms and hands, too, that could do as Steinruck wished! Massive metal hands, that had killed James Craddock, whilst Steinruck, over a mile away, had been able to look through the Thing's eyes and control its evil deeds!
And now, with the controlling apparatus broken, the Thing was running wild!
Steinruck was rushing to it, shrieking madly. Clearly his brain had snapped under the shock; the man whose mechanical genius had produced the wonder had become a raving imbecile.
Over the grass he rushed, waving his arms, as if to drive the monster back. It came on blindly, and they saw Steinruck go down before it — saw one of the steel-shod feet of the monstrosity grind him to the earth. It passed on, leaving its maker dead behind it; on towards the cliffs!
Frozen motionless with wonder, the three watched it smash through the shrubberies in its blind march. It reached the edge of the cliff, did not pause. Over the brink the monster strode uncontrolled, pitched forward, arms tossing, and vanished. They heard a great splash, and the threshing of water, then silence, save for the mutter of the waves below.

It was some time later that they found that Steinruck's real name was McQuay, and that he was the brother of a man whom James Craddock had wronged; the man who had sworn to kill him in revenge for the wrong done to him.
But the secret of the monster was never discovered. At low tide, the smashed remains of the Thing were found among the seaweed-covered rocks, twisted and torn. And, with the apparatus in the house on the headland smashed too, Steinruck's amazing secret perished with him.
"No wonder Pedro couldn't follow the scent of those footprints," said Tinker later. "There was no scent to follow! He can tackle a human scent all right, but a machine — even a human-machine — is off his mark!"
"No, Pedro hasn't lost any marks over this case," agreed Sexton Blake. "In fact, he's added to his glory!"