. Frank, Balch, our first officer, and I were in the captain's
chart-room. It was 4 P. M.--our Earth starting time. We were sixteen
hours upon our voyage.

I found Johnson in his office in the lounge. "Captain wants to see you.
Close up."

He closed his window upon an American woman passenger who was demanding
details of Martian currency, and followed me forward. "What is it,
Gregg?"

"I don't know."

Captain Carter banged the slide upon us. The chart-room was insulated.
The hum of the current was obvious. Johnson noticed it. He started at
the hostile faces of the surgeon and Balch. And he tried to bluster.

"What is this? Something wrong?"

Carter wasted no words. "We have information, Johnson--there's some
under cover plot here aboard. I want to know what it is. Suppose you
tell us frankly."

* * * * *

The purser looked blank. "What do you mean? We've gamblers aboard, if
that's--"

"To hell with that," growled Balch. "You had a secret interview with
that Martian, Set Miko, and with George Prince!"

Johnson scowled from under his heavy brows, and then raised them in
surprise.

"Did I? You mean changing their money? I don't like your tone, Balch.
I'm not your under-officer!"

"But you're under me," roared the captain. "By God, I'm master here!"

"Well, I'm not disputing that," said the purser mildly. "This fellow
Balch--"

"We're in no mood for argument," Dr. Frank cut in. "Clouding the
issue."

"I won't let it be clouded," the captain exclaimed. I had never seen
Carter so choleric. He was evidently under a tremendous strain. He
added,

"Johnson, you've been acting suspiciously. I don't give a damn whether
I've proof of it or not--I say it. Did you, or did you not meet George
Prince and that Martian last night?"

"No, I did not. And I don't mind telling you, Captain Carter, that your
tone also is offensive!"

"Is it?" Carter suddenly seized him. They were both big men. Johnson's
heavy face went purplish red.

"Take your hands!--" They were struggling. Carter's hands were fumbling
at the purser's pockets. I leaped, flung an arm around Johnson's neck,
pinning him.

"Easy there! We've got you, Johnson!"

* * * * *

Snap tried to help me. "Go on, bang him on the head, Gregg. Now's your
chance!"

We searched him. A heat-ray cylinder--that was legitimate. But we found
a small battery and eavesdropping microphone similar to the one