Arthur Jerome stood calling to me from his stateroom door at the bow superstructure corner. He was in his nightrobe with a negligee hastily wrapped around him. "Yes--" I gasped. "Brenda Carson. She--" "And I heard something about radio-helio room wrecked." The big, florid television lecturer seemed in a panic. Experienced space-traveler, but he had never run into anything like this before. I wouldn't blame him for his terror. But I had no time for him now. The ship was in confusion. I could hear the Martians, below deck in the bow, shouting with frightened questions. Two or three members of the crew were running up to Captain Wilkes who was outside his turret calling down orders. I ran down the side deck. One of the excited crew stopped me. "You seen young Philip Carson? Captain wants him." I shook my head and ran on. Somebody else was calling Carson's name. I mounted the companionway to the superstructure roof. Had Philip Carson vanished? They couldn't find him? Well, what I knew about Philip Carson now I'd certainly tell Captain Wilkes! Suddenly I realized fully that because of Brenda I had wanted to keep silent--but there was no need of that now. From the superstructure roof, as I ran forward along it, I could see down to the side deck. A cloaked figure there. Philip Carson. I had just a glimpse as he darted into a door under me. A ladder was nearby. My little paralyzer-gun was in my hand as I climbed down the ladder, reached the dark side-deck. The commotion was all up forward; there was no one here at the moment. The corridor door into which Carson had run was beside me. I ran into it, ten feet or so and into a cross corridor. Came to his doorway. It was locked. I ran around to the deck again. His window was near here. The glassite pane of the window was closed and locked. The inner fabric-shade was drawn down. What was he doing in there? Searching for his map? For other things which might be incriminating? I had a few instruments hidden in my clothes, tiny devices which we of the Interplanetary Patrol sometimes have occasion to use--a small electric listener and a tiny X-ray fluoroscope screen. The listener yielded the sound of a man's panting breath, his furtive, fumbling movements within the dark little cubby. Then I tried the X-ray, through the fabric-shrouded glassite pane of the window. It shot its invisible, soundless rays through the window into the cubby. The little hooded three-inch screen in my palm glowed with the greenish fluoroscopic X-ray image. A kneeling skeleton was revealed--the skeleton of a man kneeling in there with his back to me. I stared, and suddenly gasped, with my breath stopped. The back of the skeleton's skull was visible--the image-shadow there was of a different density from the bones of his skull! A dark triangular patch--not bone, but metal! The man with the metal skull! Philip Carson, of notorious Chameleon fame! The Phantom raider! I had him here identified at last! Had him trapped here!