"My first voyage too," I said. I started on; then turned back. "By the way, have you seen Mr. Polter? I was looking for him." "The Purser, sir? I'm thinkin' he should be in his office." I nodded; turned the superstructure corner; went into the main corridor. Polter's little office cubby had a light in it. He was sitting there casting up his accounts. Jim Polter. I had heard half a dozen people call him that. Nina's voice came echoing back into my mind.... "No--no Jim, don't--" Was this the fellow who had climbed out of her window just a few moments ago? His desk light illumined his squat, thick-set figure. He was a man of perhaps forty. He glanced up at my step. "Hello, Mr. Penelle. You're up late." "Just going in," I said. Polter was smoking. The fragile ash on the little white paper cylinder was nearly an inch long. I passed on. At Nina's door I briefly paused. There was no sound. The ventilator grille overhead was dark now. Upon impulse I pressed her buzzer. "Yes? Who is it?" "It's I. Fred Penelle." Her door opened an inch; the sheen of light in the corridor showed her white face framed by the flowing black hair. A wave of her perfume came out to me. "What--what is it?" she murmured. "Are you all right?" I whispered lamely. "Yes. Yes--of course." And she added still more softly, "You're taking too much chance--here like this. The Captain--did you tell the Captain--what I told you--" "I'm going there now." She closed the door. I stood with the sudden realization that I might be going beyond my job as an S.S. Man; my personal interest in this girl leading me to pry into her private affairs. But the feeling was brief. The terror was still in her eyes; I could not miss it. I decided then to go to Mackensie in the control turret. Someone had tried to melt into the helio room. Mackensie must be told it. Heaven knows, there never had been an S.S. Man who felt as helpless as I did at that moment. I could not determine whether I should tell the Captain what I had seen and heard in Nina's room, or not. How much Mackensie himself knew of what might be going on, I could not guess. And there was not another person on the _X-87_ whom I could trust! It was as though I were wholly alone here, with lurking murderers in every shadow, watching their chance--waiting perhaps for a predetermined time when they would come into the open and strike. * * * * *