A rasping voice in the cabin doorway sounded behind me. Gun in hand, I whirled. One of the huge deckhands stood there, murder on his face, a blood-stained knife between his teeth so that he looked like an ancient picture of a surface vessel pirate. He lunged in at us. My flash caught him full in the face; horribly his features blackened as he went down. "Oh--Oh, I had no chance to let you out!" Nina was half sobbing it as she flung herself down over the box. The ship's alarm siren had suddenly died. Did that mean that the captain and the others in the control turret had been killed? The thought stabbed at me. Distant shots were still sounding. The oaths of fighting men were audible--the loyal members of the crew, fighting those traitors who had so suddenly set upon them. Footsteps were thudding on the roof-deck overhead. "No chance to let you out!" The pallid girl with trembling fingers was fumbling at the box. Its lid rose up, with the head and shoulders of a man appearing beneath; a man entombed, hiding in there, breathing with the air-renewers of the ticking mechanism. A stalwart man of iron-gray hair. Georg Blake! Nina's father. I recognized him from the many pictures I had seen. He leaped out of the box, stared at me. "A Government man," Nina gasped. "Here to help us." The report of Blake's death--his possible murder--all that had been Blake's own doing. He gripped me now; murmured it swiftly. A giant, dominant fellow, he towered over me. Nina was unpacking his weapons from the box as he told me. He had believed there was a plot on the Moon against him; was smuggling himself to the Moon, where in secret, with the villains thinking him dead and only his young daughter to cope with, he expected to expose them. And most of the voyage he had been hidden in the box, afraid of eavesdroppers or some prying Benson curve-ray. "Give me those guns, Nina. These damnable murderers--" Then he swung at me; lowered his voice: "Mackensie has the catalyst?" "Yes," I murmured. "Good! I know where. By Heaven, they can kill us both and still they won't find it." He was buckling his weapons to his huge belt. "The captain's in the control turret," I said. "Making a stand up there. We should go to him." "Yes. You're right. Come on."