He brought out the one stock certificate he had taken from the bank’s vault, set to work immediately. His eyes shone with a bright, eager light as he studied that harmless looking oblong of paper. The company’s name was carefully engraved upon it, together with the date of issue, the dividend it was supposed to pay, and the corporation rulings.
With a small hand-glass Agent “X” went over every inch of both sides, but he raised his head unsatisfied. Next he took a bottle of colorless fluid end applied it deftly over the face of the stock issue. This liquid was mixed to bring out secret inks. But nothing showed.
The Agent applied heat now; patting the stock on a flat electric warming plate, careful not to burn it. Still no writing or marking was revealed.
He nodded to himself, turned to a square glass cabinet that reposed on a shelf. He took this down. It was air-tight, with a small motor and air pump attached. He placed the stock certificate inside the cabinet face upward, started the motor pump going, and exhausted the air within.
When a small dial showed that a vacuum existed inside, the Agent dropped some white crystals in an attached receptacle. Carefully he fitted a screw cap over the receptacle, lighted a small burner under it, then opened a tiny valve in the slender brass pipe that passed into the cabinet.
He was submitting the stock certificate to the most delicate test known to detect secret writing — the sublimated iodine test used by Captain Yardley and others of the American Secret Service during the World War.
A heavy, purplish vapor appeared inside the glass cabinet as the iodine crystals heated. The vapor descended sluggishly on the face of the stock certificate. It settled into the very pores of the paper; filling every minute depression in its fibers. And, when the vapor lay like a dark, unwholesome smoke barrage over the face of the stock certificate, Agent “X” opened the cabinet and took the document out.
Then breath hissed between his teeth. His eyes became like pin-points of polished steel. For, on the white surface of the stock issue, something had appeared. It was the lifelike, spine-chilling outline of a horrible creature — an octopus with tentacles extended and beak thrust forward. This was the secret marking that the other tests had failed to show up until the sublimated iodine vapor had forced its startling revelation.
Chapter VI
FOR seconds Agent “X” stared down at this ghastly symbol. There was no name, no number — only this hideously realistic outline of the octopus. It set the stock issue apart as though some devilish curse had been laid upon it. “X” guessed it had significance far deeper than appeared. The mark had been placed there by a masterly brain to guard against the possibility of forgery. It appeared as a sinister warning to any one bold enough to attempt an imitation of this paper.
Agent “X” put his vacuum cabinet away. In the fresher air of the room, the iodine vapor evaporated, and the strange mark was slowly vanishing. At the end of two minutes it had entirely gone. The stock appeared unmarked, innocent again. Agent “X” pocketed it.
It was now nearly four in the morning. The Agent had had no sleep. But, while working on a case, he seldom indulged in rest. Dynamic, indefatigable forces appeared to drive him on.
He left the hideout as he had come, walked swiftly to his parked roadster. Once more he headed the car toward the suburbs. He had another definite objective now. The discovery of the octopus seal on the stock had opened up a new line of investigation.
The whole city was cloaked with the chill darkness that precedes dawn. Somewhere far away the dull rumble of a truck sounded. Fitful wind stirred the branches of the trees as he came to the suburb. All else was still.
Bill “Diamond” Quade’s address was in the secret file of the Agent. He had taken pains to learn it when the mysterious tip-off had come. Quade, luxuriating in new-found prosperity, had bought a huge house in a fashionable suburb of the city. He had sold his gambling establishment, joined a country club, taken to bridge, golf and horseback riding. Many of his new friends were unaware of his shady past.
Agent “X” left his car a block away. He vaulted over the stone fence surrounding the Quade estate, strode quickly across a dark lawn toward a big house.
Somewhere a chain rattled. Agent “X” stopped. He listened for seconds, then gave a low, peculiar whistle. It was faint, musical, with a ventriloquistic quality. It was the whistle of Secret Agent “X”—unique in all the world.
In the darkness beyond a dog growled softly. Agent “X” repeated his strange whistle. It was not loud enough to carry inside the house. It was meant for the dog’s ears only. The animal’s growl changed to a low whine. Agent “X” approached quietly.
A huge police dog was chained in front of a kennel. “X” walked forward confidently, patted the dog’s head, spoke a few low-voiced sentences. His uncanny ability in making friends with animals had stood him in good stead often before.
“Quiet, old fellow,” he whispered. “Stay out of this.”
He strode on toward the house, leaving the dog gently thumping its tail on the ground.
There were double locks on the doors of the Quade mansion, tightly closed shutters on the windows of the ground floor. Quade’s contact with the underworld had made him suspicious, apparently. These locks gave Agent “X” trouble. He discovered, too, by probing with his small flash that the doors and windows on this first floor were protected by a delicate alarm system. The wires of it were deep inside the framework.
He shrugged, glanced about him. Huge trees towered over the big house on the west side. He glimpsed the dim outlines of a porch roof.
His rubber-soled shoes, of special pliant leather, were light, skid-proof. He crossed quickly to a big tree, studied its branches for a moment. Crouching low, muscles tautly balanced, he leaped suddenly straight upward, swift and dexterous as a cat, and caught the lower branch of the tree. In a moment he had pulled himself up.
HE climbed to another branch higher still, swung along hand over hand, dropped lightly to the top of the porch roof, landing on his toes.
This window was unshuttered; but a minute inspection showed that the same complex electric alarm system was wired here.
The Agent took out his tool kit, selected a small diamond-set glass cutter. Quickly but quietly he drew this around the glass just inside the sash. When the lines were complete he took a small rubber suction cap from his pocket, pressed it to the glass. It clung closely as a burr to clothing.
Delicately he pressed with his fingers against the glass. There came one faint, quick snap as the glass broke along the lines he had cut. It did not fall inwards, for his suction cap held it. He turned the glass edgewise, lifted it out and laid it down on the roof away from the window. In a moment he was inside the house.
There was a bed in the room he entered; but it was unoccupied. There were many vacant rooms in this big house which Quade’s egotistic love of display had made him buy.
Agent “X” tiptoed out into the hallway. A thick carpet deadened his footsteps here. He came to the top of a flight of stairs, moved softly down them. When he reached the bottom he clicked his flash on again for a moment, fingers held over the small lens so that only the thinnest ray of light came through.
With this to guide him he prowled about the lower floor of the house till he had located a room which gave evidences of being Quade’s den. There was a liquor cabinet here, smoking paraphernalia, a big roll-top desk. The Agent’s eyes gleamed brightly as they fell on this.
Before opening it, he crossed the hall outside and located the hidden, inside switch which disconnected the burglar alarm. He opened it, unlocked a side door. This would give him a quick exit in case an emergency arose.