I had not been able at first to understand why Captain Carter wanted Miko left at liberty. Within me there was that cry of vengeance, as though to strike Miko down would somehow lessen my own grief at Anita's loss. Whatever Carter's purpose, Snap had not known it. But Balch and Dr. Frank were in the captain's confidence--all three of them working on some plan of action. Snap and I argued it, and thought we could fathom it; and in spite of my desire to kill Miko, the thing looked reasonable. It was obvious that at least two of our passengers were plotting with Miko and George Prince; trying during this voyage to learn what they could about Grantline's activities on the Moon; scheming doubtless to seize the treasure when the Planetara stopped at the Moon on the return voyage. I thought I could name those masquerading passengers. Ob Hahn, supposedly a Venus Mystic. And Rance Rankin, who called himself an American magician. Those two, Snap and I agreed, seemed most suspicious. And there was the purser. With my hysteria still on me, I sat for a time on the deck outside the chart-room with Snap. Then Carter summoned us back, and we sat listening while he, Balch and Dr. Frank went on with their conference. Listening to them I could not but agree that our best plan was to secure evidence which would incriminate all who were concerned in the plot. Miko, we were convinced, had been the Martian who followed Snap and me from Halsey's office in Great-New York. George Prince had doubtless been the invisible eavesdropper outside the helio-room. He knew, and had told the others, that Grantline had found radium-ore on the Moon--that the Planetara would stop there on the way home. * * * * * But we could not incarcerate George Prince for being an eavesdropper. Nor had we the faintest tangible evidence against Ob Hahn or Rance Rankin. And even the purser would probably be released by the Interplanetary Court of Ferrok-Shahn when it heard our evidence. There was only Miko. We could arrest him for the murder of Anita. But the others would be put on their guard. It was Carter's idea to let Miko remain at liberty for a time and see if we could not identify and incriminate his fellows. The murder of Anita obviously had nothing to do with any plot against the Grantline Moon treasure. "Why," exclaimed Balch, "there might be--probably are--huge Martian interests concerned in this thing. These men here aboard are only emissaries, making this voyage to learn what they can. When they get to Ferrok-Shahn they'll make their report, and then we'll have a real danger on our hands. Why, an outlaw ship could be launched from Ferrok-Shahn that would beat us back to the Moon--and Grantline is entirely without warning of any danger!"