The Mystery of the Fifteen Sounds

Without waiting for the gelatin to harden, Roger summoned the staff and his cousin to the screening room. As soon as they had set their wrist watches with the observatory time s...

"I have heard the voices that seem to come out of nowhere," the experimenter explained. "I have traveled in the Oriental countries. I have heard strange things; and I have _seen...

"Of the whole staff you are the only man I need _not_ suspect," Grover saw deeper into things than had Roger. "It is an old trick, to turn suspicion toward an innocent man by 'p...

"Go down and draw the fuse again," Grover suggested. "Queer that I did not think of that simple way to nullify all our protection. It explains how the safe was so easily opened,...

Whatever was in the laboratory, it was coming straight up to the second floor. Roger, crouched beside the floor outlet to await a signal to plug in and electrify that chair, won...

"The staff will be arriving any time, now," said he. "Let's look up that fellow, Joseph Z. Clark, because I want you to do a little Sherlock-Hawkshaw work if we locate his addre...

To be involved in a mystery in the laboratory was thrilling; but to have a share in restoring the Eye of Om, evidently a priceless gem, would be more so.

"Just the telephone," his thirty year old cousin, head of the laboratory, called from his room beyond the adjoining bath. Roger, who was already on his way to the downstairs lib...

"The mystery of the white rats, supposed to be deadly menaces because we thought they were inoculated with germs of a spinal malady, got our attention turned to every possible i...

"You lock up securely and make certain that the devices all work." Grover said, as they separated, "I shan't have to stay with the old man, because it isn't expected that he wil...

When Doctor Ryder had been allotted space in which to conduct his experiments to see if he could perfect a cure for a horribly deadly spinal affliction, he had decided to experi...

It did give him a little twinge of dismay, a slight blow to his vanity, to discover that during his absence Toby Smith had been put to work in the stock and supply department. T...

Zendt, quiet, calm, thorough, had been in Australia, his own record attested. Mr. Ellison, than whom no one was more clever in electrical matters, had built power plants for a b...

Roger's mind was more at ease. He had seen Mr. Clark pocket the gem for which they substituted their Eye of Aum. Outside the rock door as they emerged from the fissure leading d...

He had only imaginative evidence against any of the names he had inserted in his diary-like notations. As he scanned his list Roger saw that he had done less interpreting than s...

"No need," Grover laughed, "with its partner, the ape, bound. There is no way to get out of that hide." He gestured toward the cabinet. "There it is, just as you hid it, the Tru...

Soon Roger felt that he had given the gases time to flow down, to produce at least inertia or coma. He must not dally too long. He scrambled up the rain-drain as he had previous...

"What a break!" Tip, whose companionship the man readily agreed to, as Tip carried the portable battery, compact five-tube set, telephone instrument and spare B. battery, spoke...

Potts, on Grover's instructions, had made the room installation. To "get back" at his chum for the suspicion about the Eye of Om, the handy man could have made that "Fire" cry o...

Rooms that were locked and barred he had read about in detective stories; they had been entered. A room not only so sealed but, far better, sealed by locks that not even Potts o...

"I knew it would be. We left Tip to take turns watching with the men from the Falcon Patrol Agency. Two at a time, one on each floor. But I never count on human watchmen alone....

First of all, it was the one animal able to climb down a rope from the skylight on the roof, which it could have reached by being taken up the fire-escape on a candy factory nex...

During Grover's absence at the hospital, the staff began to arrive. Until the secretary should come to handle the switchboard Doctor Ryder volunteered to be monitor on calls, be...

No other plan seemed so likely to be fruitful. If he was supposed to be in the dark-room, his presence in the office must show to some guilty person that Roger was equally alert...

Without consulting his list, because he did not want to have it in sight any more than he wanted its place in the files discovered, Roger used the "thinking den" for just what i...

While Tip was rushed out to the street, to drive Grover's car to and fro, and all around, in pursuit of the elusive, uncanny pair--or had the man left Doctor Ryder elsewhere?--R...

"But why must you restore the Eye, at so much risk?" Grover, put in possession of facts already known to Roger, asked, "Turn it over to those mysterious Tibetans who open safes...

With every effort of will he held his muscles steady when he wanted to run. Clear faculties would be all he had left to pit against an adversary certainly more than simply vindi...

Zendt was either a master of facial control or he was one of those "innocent bystanders" who manage to intrude when some crucial point of a drama is about to be played.

"Fortunately, it was not fatal," Grover continued, "and I stayed here less to hear him, for I knew that would not be probable. I was here to protect him if anyone, knowing he li...

Across the Tibetan plain, with its sparse vegetation and occasional small and always distant group of rude huts surrounded by the grazing herd of the tiny community, the party m...

That did not concern him overmuch. Roger knew that the safe protection was a separate circuit from those he had cut out when he had unfastened the door on arriving. Besides, he...

"But he was so clever," protested Clark, "and surely if anybody ever could interpret what that temple must hide in that queer sound, he'd be the one. He interpreted claws on gla...

Since Astrovox would be away for a good while and his experiments could hardly be picked up by anyone else, Roger was told to arrange a temporary home for the rabbits, squirrels...

"In the first place, assuming that a shot had been fired, you see that there is no inkwell on the desk and that the picture of my sister has been knocked over or has fallen over."

"No. You will adjust the big sun-lamp so it sends rays upward. Put the blue filter from the star-reader's plant beds on it. It is only fair that part of his equipment should hel...

Astrovox, well recovered from his blow on the temple, was going to "shoot" the stars as they crossed over the lens of his telescope and Roger was getting a sound-film into a cam...

"Oh, no you don't," Grover spoke for the first time during the interview, "there is a matter of a vanished scientific student of the stars, a shot prior to his disappearance, an...

When they had gotten back, to report to Doctor Ryder the substitution for the false Eye of the one they had brought, Potts had seemed uneasy, though Roger had accepted the man's...

With an abrupt change the atmosphere seemed to be charged with electricity. Of course, thought Roger, trying to remain cool, it was merely his fear of the outcome that made his...

Roger, finally, decided that there was one sure and final word to be said by chemistry. If, as Ellison insisted, other chemicals than actual burning gas caused the inside of the...

Instead of shouting, beating on the door and otherwise wasting energy and using up the available oxygen of the room, Roger paused, taking only the precaution of mounting on a hi...