Bigman looked at him doubtfully. "Listen, you're try- ing to sell me a bale of space dust." He turned abruptly and moved away. "I think I'll look at the book after all."

The Hilda moved on and took a new position, while the microwaves shot out, searching and searching. Then again it moved. And again. Slowly Lucky was screening the underwater plateau on which the city of Aphrodite stood.

He waited grimly at the instruments. Somewhere down here his friend Lou Evans must be. Evans's ship could navigate neither air nor space, nor any ocean depth of more than two miles, so he must be confined to the relatively shallow waters of the Aphrodite plateau.

The first answering flash caught his eye even as he repeated the must to himself for the second time. The microwave feedback froze the direction finder in place, and the return pip was brightening the entire receiving field.

Bigman's hand was on Lucky's shoulder instantly. "That's it! That's it!"

"Maybe," said Lucky. "And maybe it's some other ship, or maybe it's only a wreck."

"Get its position, Lucky. Sands of Mars, get its position!"

"I'm doing it, boy, and we're moving."

Bigman could feel the acceleration, hear the churning of the propeller.

Lucky leaned closely over the radio transmitter and its unscrambler, and his voice was urgent. "Lou! Lou Evans! Lucky Starr at this end! Acknowledge signals! Lou! Lou Evans!"

Over and over again, the words pushed out along the ether. The returning microwave pip grew brighter as the distance between the two ships grew less.

No answer.

Bigman said, "That ship we're pipping isn't moving, Lucky. Maybe it is a wreck. If it were the councilman, he'd either answer or try to get away from us, wouldn't he?"

"Sh!" said Lucky. His words were quiet and urgent as he spoke into the transmitter: "Lou! There's no point in trying to hide. I know the truth. I know why you sent the message to Earth in Morriss's name asking for your own recall. And I know who you think the enemy is. Lou Evans! Acknowledge…"

The receiver crackled, static-ridden. Sounds came through the unscrambler and turned into intelligible words: "Stay away. If you know that, stay away!"

Lucky grinned his relief. Bigman whooped.

"You've got him," shouted the little Martian.

"We're coming in to get you," said Lucky into the transmitter. "Hold on. We'll lick it, you and I."

Words came back slowly, "You don't-understand-

– I'm trying to…" Then, almost in a shriek, "For

Earth's sake, Lucky, stay away! Don't get any closer!"

No more came through. The Hilda bored toward the position of Evans's ship relentlessly. Lucky leaned back, frowning. He murmured, "If he's that afraid, why doesn't he run?"

Bigman didn't hear. He was saying jubilantly, "Terrific, Lucky. That was terrific the way you bluffed him into talking."

"I wasn't bluffing, Bigman," said Lucky, grimly. "I know the key fact involved in this whole mess. So would you, if you stopped to think about it."

Bigman said shakily, "What are you getting at?"

"Do you remember when Dr. Morriss and you and I entered the small room to wait for Lou Evans to be brought to us? Do you remember the first thing that happened?"

"No."

"You started laughing. You said I looked queer and deformed without a mustache. And I felt exactly the same way about you. I said so. Remember?"

"Oh, sure. I remember."

"Did it occur to you to wonder why that was? We'd been watching men with mustaches for hours. Why was it that the thought suddenly occurred to both of us at that particular time?"

"I don't know." "Suppose the thought had occurred to someone else who had telepathic powers. Suppose the sensation of surprise flooded from his mind to ours."

"You mean the mentalist, or one of them, was in the room with us?"

"Wouldn't that explain it?"

"But it's impossible. Dr. Morriss was the only other man…Lucky! You don't mean Dr. Morriss!"

"Morriss had been staring at us for hours. Why should he be suddenly amazed at our not having mustaches?"

"Well, then, was someone hiding?"

"Not hiding," said Lucky. "There was one other living creature in the room, and it was in plain view."

"No," cried Bigman. "Oh, no." He burst into laughter. "Sands of Mars, you can't mean the V-frog?"

"Why not?" said Lucky calmly. "We're probably the first men without mustaches it ever saw. It was surprised."

"But it's impossible."

"Is it? They're all over the city. People collect them, feed them, love them. Now do they really love V-frogs? Or do the V-frogs inspire love by mental control so as to get themselves fed and taken care of?"

"Space, Lucky!" said Bigman. "There's nothing surprising about people liking them. They're cute. People don't have to be hypnotized into thinking that."

"Did you like them spontaneously, Bigman? Nothing made you?"

"I'm sure nothing made me like them. I just liked them."

"You just liked them? Two minutes after you saw your first V-frog, you fed it. Remember that?"

"Nothing wrong with that, is there?"

"Ah, but what did you feed it?"

"What it liked. Peas dipped in axle g…" The little

fellow's voice faded out.

"Exactly. That grease swelled like axle grease. There was no mistaking what it was. How did you come to dip the pea in it? Do you always feed axle grease to pet animals? Did you ever know any animal that ate axle grease?"

"Sands of Mars!" said Bigman weakly.

"Isn't it obvious that the V-frog wanted some, and that since you were handy it maneuvered you into delivering some-that you weren't quite your own master?"

Bigman muttered, "I never guessed. But it's so clear when you explain it. I feel terrible."

"Why?"

"It's a hateful thing, having an animal's thoughts rolling around inside your head. It seems unsanitary." His puckish little face screwed up in an expression of revulsion.

Lucky said, "Unfortunately, it's worse then unsanitary."

He turned back to the instruments.

The interval between pip and return disclosed the distance between the two ships to be less than half a mile when, with surprising suddenness, the radar screen showed, unmistakably, the shadow of Evans's ship.

Lucky's voice went out over the transmitter. "Evans, you're in sight now. Can you move? Is your ship disabled?"

The answer came back clearly in a voice torn with emotion. "Earth help me, Lucky, I did my best to warn you. You're trapped! Trapped as I'm trapped."

And as though to punctuate the councilman's wail, a blast of force struck the subship Hilda, knocking it to one side and jarring its main motors out of commission!

In bigman's memory afterward, the events of the next hours were as though viewed through the reverse end of a telescope, a faraway nightmare of confused events.

Bigman had been slammed against the wall by the sudden thrust of force. For what seemed long moments, but was probably little more than a second in actuality, he lay spread-eagled and gasping.

Lucky, still at the controls, shouted, "The main generators are out."

Bigman was struggling to Ms feet against the crazy slope of the deck. "What happened?"

"We were hit. Obviously. But I don't know how badly."

Bigman said, "The lights are on."

"I know. The emergency generators have cut in."

"How about the main drive?"

"I'm not sure. It's what I'm trying to test."

The engines coughed hoarsely somewhere below and behind. The smooth purr was gone, and in its place a consumptive rattle sounded that set Bigman's teeth on edge.

The Hilda shook herself, like a hurt animal, and turned upright. The engines died again.