A metallic voice was speaking.
"— distance from the sun to Mercury is thirty-six million miles. To Venus it is sixty-seven million miles—"
The psychophone suspended over John Thorn's head droned on in its monotonous metallic voice, speaking his thoughts.
He sat in one of the blue-lit cells, bound by broad leather straps into a chair. Sual Av and Gunner Welk sat nearby, similarly bound. And they too had psychophones attached by thin black wires to tiny incisions in the back of their skulls.
"— distance to Earth is ninety-three million miles. Earth — doomed now and my fault. They'll never get that radite that would — no, don't think of that! Distance to Mars, a hundred and forty-one million miles! To Jupiter—"
Thorn was desperately trying to keep his mind upon abstract things and figures. For two days and nights he and his comrades had sat bound here like this. Time had become meaningless, and it seemed to him that be had sat here thus forever, trying to think of anything except what Haskell Trask wanted to know.
Trask had ordered psychophones attached to the captured Planeteers. For Trask knew now that the Planeteers were secret agents of the Alliance, and that they were after the Erebus radite. The dictator had learned that from Lana's psychophone record, which had transcribed the information when Thorn had told it to her through the door of her cell.
"So that is why the Planeteers have seemed to blunder into so many of our secrets in these last few years!” Trask had exclaimed. “It wasn't blundering, but deliberate purpose."
"If they were out to get that radite for the Alliance, that must mean that the Alliance has some plan of using the radite against us!” Jenk Cheerly had pointed out shrewdly.
"Why did the Alliance send you to get the radite?” Trask had demanded of the Planeteers.
Thorn and Gunner and Sual Av had remained silent. And the tall, bony dictator had been seized by one of his rages.
"You refuse to tell? Then you shall sit with psychophones attached to you until your thoughts disclose why the Alliance wants that radite!
"See to it, Cheerly,” the dictator had ordered the fat spymaster. “And put the girl back under the psychophone again and keep her there until she yields the secret of Erebus."
Thorn had seen Lana dragged back into her cell, before he and his comrades were placed in another cell. The tiny incisions in their skulls had been rapidly made, and the little electrodes of three psychophones inserted. And they had sat here ever since, the remorseless mechanisms speaking and recording all their conscious thoughts.
John Thorn's mind hovered on the brink of absolute despair. It was Lana he was thinking of. The girl, he knew, could not withstand the awful strain of this diabolical mental inquisition much longer. She would surely soon give way under the strain and let her mind wander to the secret that their captors wanted.
"— if she does, it's the end of everything,” the psychophone above spoke Thorn's thoughts. “She mustn't—"
Then, discovering that he had let his mind stray from abstract things, Thorn fiercely forced his thoughts back to safe subjects. He made himself concentrate on interplanetary history.
"The first space-flight was made by Robert Roth in nineteen-ninety-six. Roth visited Venus and Mars, and in two thousand and one made a second flight to Jupiter and Saturn, but crashed upon his return to Earth and lived only two days. After his death his chief aide, Clymer Nison, visited Uranus, Neptune and Pluto, but Clymer Nison never returned from an attempt he made to visit Erebus—
"Keep your mind off Erebus! If you think of Erebus, you'll think of the radite and the Alliance weapon — keep thinking of interplanetary history! First permanent colonies established on Mars and Venus by two thousand and eighty-five. By twenty-one-fifty all the planets from Mercury to Neptune had been colonized. The first independence movements started in twenty-four-seventy, and by two centuries later, all the colonized planets had become independent worlds."
As Thorn desperately strove to keep his mind concentrated on interplanetary history, his two comrades were using similar stratagems to keep from revealing any information.
He could hear the psychophone attached to Sual Av blaring forth the bald Venusian's thoughts. “-and then there was that fat girl on Callisto — what the devil was her name?” Sual Av was thinking. “Can't remember her name, but I do remember that she was plenty big. Callisto's gravitation was so weak that she seemed light as a feather, but if I'd held her on my knee on any other world, she'd have flattened me! And then that tiger-cat of a Martian wench I met when I was engineer at the Syrtis chromium mines. Tried to knife me one night—"
Sual Av was obviously thinking of all the girls he had ever known, to occupy his thoughts safely. But Gunner Welk's psychophone was pouring forth a much different stream of thoughts.
The big Mercurian, ever since their incarceration under the psychophones, had occupied himself in thinking of what he would do to Haskell Trask if the opportunity ever offered.
"— glue his eyelids open and stake him out on the hot side of Mercury to look at the sun a while. No, he'd die too quick that way! It'd be better to take his skin off with that acid the Jovian tanners use, and then—"
The cell was like a bedlam to John Thorn's dazed mind. The three psychophones blaring metallically and without pause had become a torment to his ears.
He felt that he could not stand this much longer. And he understood now the full horror of the days that Lana had spent under the relentless instrument. And Lana was again being tortured by the psychophone!
On and on the hours dragged. The blue-lit cell swam about Thorn, and he closed his eyes tightly. Yet still the remorseless machine blared his thoughts, repeating interplanetary history, chemical formulae, mathematical tables — anything that would keep his mind on safely abstract subjects.
Thorn had cudgeled his mind for a means of escape. But there seemed none. He and his comrades were bound into their metal chairs by the broad leather straps. The door of their cell was secured by one of the invulnerable wave-locks. And two guards — two of Cheerly's Secret Police this time — stood on constant duty out in the dungeon corridor.
Thorn dozed finally. It was his only escape from the torment of the blaring psychophone. Yet he could sleep for but a brief period at a time, and he was dully unsurprised when he awakened a little later.
He went rigid in his bonds. He had been awakened by the entrance of Jenk Cheerly into their cell.
The Uranian spymaster's puffy green face showed suppressed excitement. His little eyes were gleaming triumphantly.
"You Planeteers may as well give up and tell why the Alliance wants the radite, now,” he said exultantly.
Thorn made no vocal answer, but his raging thoughts blared from the psychophone.
"If I could just close my hands on that fat throat — just once—"
The psychophones of Sual Av and Gunner were voicing similar thoughts as they gazed with blazing eyes at Cheerly.
The fat Uranian sneered. “It's too bad you lads still feel that way. For the Alliance will never get the radite now, anyway. The League is going to get it. Lana Cain has just given up the secret of Erebus at last!"
"That's a lie!” John Thorn shouted. “A trap to make us talk!"
"It's the truth.” Cheerly taunted triumphantly. “Did you think the girl could go on forever without thinking of the secret? The more she tried not to think of it, the more her mind turned toward it. You'll find out the same thing will happen to you."
There was such visible triumph and excitement in the Uranian's fat face that Thorn felt a pang of fear.
At that moment there was a clang of opening doors, and a tramp of feet. Haskell Trask strode into the cell, his bony face and deep eyes ablaze with excitement.
"You reported that the girl has finally told what she knows about Erebus, Cheerly?” the dictator exclaimed.
"Yes, sir,” answered the obese spymaster triumphantly. “Her mental control finally weakened, and she thought of what her father had told her. The psychophone put it all into the record.
"With what she told to guide us, we can land safely on Erebus and get the radite, sir!” the Uranian continued exultantly. “We wouldn't have had a chance without her secret. For it seems that there's only one spot on Erebus where men can land without meeting a ghastly fate."
Haskell Trask's pale green, bony face twitched with visible emotion. The dictator's gloomy eyes flashed.
"You'll sail at once for Erebus and get the radite!” he ordered Cheerly. “A naval cruiser is waiting in the court now. As soon as you get the radite and start back with it, flash word to me by audio. When I get your message, I'll order our fleets to blast sunward at once for the attack on the Alliance."
His fists clenched. “Then at last our day will have come! Even while our fleets are crushing the Alliance navies, we will be making that radite into bombs that will break the resistance of the inner worlds utterly."
"I'll take the girl and a psychophone with me to Erebus, sir,” Cheerly said shrewdly. “She may know a little more about Erebus than her conscious thoughts have revealed. If that is so, I'll get it out of her."
Trask, recalled from his oratorical flight, nodded his head indifferently.
"Take her, then. But make all speed to Erebus and back. Remember, the mightiest armada in the system's history will be waiting for your message as a signal for it to sail sunward!"
John Thorn had listened in gathering horror. This was the end of all hope, surely! Cheerly would get the radite and there would be no chance for the Alliance ever to operate Philip Blaine's great secret weapon in the lunar caverns—"Philip Blaine's great secret weapon in the lunar caverns,” the psychophone attached to Thorn was blaring.
Too late, Thorn suppressed his thoughts! In his momentary horror, he had let his thoughts stray, and the psychophone over his head had been speaking them.
"Did you hear that, sir?” cried Jenk Cheerly to the dictator. “A secret weapon of the Alliance, built by the physicist Philip Blaine in the caverns of Earth's moon! That's why the Alliance wanted the radite — to operate that weapon!"
Haskell Trask's eyes snapped. The dictator strode to where Thorn sat cursing his own loss of mental control that gave the secret away.
"What is the weapon that the Alliance has hidden in the lunar caves?” he demanded of Thorn. “Speak, Earthman!"
Thorn remained rigidly silent. With a violent burst of anger, the dictator struck him across the face.
"We've got to find out what that secret Alliance weapon is!” Trask snapped to his spymaster. “There's just a chance they might be able to operate it without the radite."
"He'll give it away to the psychophone, in time,” Cheerly assured his master. “He can't help but give it away — the psychophone pulls out all their secrets, sooner or later."
"You're wrong this time,” John Thorn said bitterly. “I don't know the nature of the Alliance weapon. None of us know it — and I'm damned glad now we don't!"
"He's lying, of course,” Jenk Cheerly said calmly. “But he'll have to think the truth, sooner or later."
"We'll keep these Planeteers; under the psychophones until they do tell what that weapon is,” Trask declared harshly. “Meanwhile, don't delay, Cheerly. Get started now for Erebus!"
John Thorn writhed as Lana was brought out of her cell by two of Cheerly's men, and carried down the corridor. He could just glimpse her white, worn face through the grating in the door, and heard her despairing, sobbing cry.
"John, I gave up the secret to them. I couldn't keep from thinking of it longer! And now they're taking me with them to Erebus. Everything is lost, and it's all my fault!"
"Lana, it's not your fault!” Thorn cried hoarsely. “Lana,"
But she was gone. For a moment Jenk Cheerly's fat, green face grinned in at them through the grating. His eyes were sinister and hateful.
"Goodbye, Planeteers,” the Uranian squeaked mockingly. “Wish me a pleasant voyage to Erebus — for by the time I get back with the radite, you three will be dead!"