I moved to the lens-box of the spectroheliograph. It seemed that Snap was very strangely reluctant: Was it because he knew that the Grantline camp lay concealed on the north inner wall of Tycho's giant ring? I thought so. But Snap flashed a queer look at Anita. She did not see it, but I did. And I could not understand it. My accursed, witless incapacity! If only I had taken warning! "Here," commanded Miko. "A score of 'graphs with the zed-ray. I tell you I will comb this surface if we have to stay here until our ship comes from Ferrok-Shahn to join us!" The Martian brigands were coming. Miko's signals had been answered. In ten days the other brigand ship, adequately manned and armed, would be here. Snap helped me connect the zed-ray. He did not dare even to whisper to me, with Moa hovering always so close. And for all Miko's sardonic smiling, we knew that he would tolerate nothing from us now. He was fully armed, and so was Moa. I recall that Snap several times tried to touch me significantly. Oh, if only I had taken warning! We finished our connecting. The dull gray point of zed-ray gleamed through the prisms, to mingle with the moonlight entering the main lens. I stood with the shutter trip. "The same interval, Snap?" "Yes." Beside me, I was aware of a faint reflection of the zed-light--a gray Cathedral shaft crossing the helio-room and falling upon the opposite wall. An unreality there, as the zed-light faintly strove to penetrate the metal room-side. I said, "Shall I make the exposure?" * * * * * Snap nodded. But that 'graph was never made. An exclamation from Moa made us all turn. The Gamma mirrors were quivering! Grantline had picked our signals! With what undoubtedly was an intensified receiving equipment which Snap had not thought Grantline able to use, he had caught our faint zed-rays, which Snap was sending only to deceive Miko. And Grantline had recognized the _Planetara_, and had released his occulting screens surrounding the radium ore. The Gamma rays were here, unmistakable! And upon their heels came Grantline's message. Not in the secret system he had arranged with Snap, but unsuspectingly in open code. I could read the swinging mirror, and so could Miko. And Miko decoded it triumphantly aloud: "_Surprised but pleased your return. Approach Mid-Northern hemisphere, region of Archimedes, forty thousand toises[C] off nearest Apennine range._" The message broke off. But even its importance was overshadowed. Miko stood in the center of the helio-room, triumphantly reading the light-indicator. Its beam swung on the scale, which chanced to be almost directly over Anita's head. I saw Miko's expression change. A look of surprise, amazement came to him. "Why--"