Leaving Lieutenant Scott in the conning tower, the boys all clambered down to the floor of the float to examine the blockings which kept the submarine on a level keel. They were gone only a short time, but when they climbed up the rope ladder to the conning tower again the light was dim, and a slow, cold rain was falling. The Lieutenant was not on the conning tower, and Ned at once descended to the general living room of the submarine. Before he reached the middle of the stairs the lights, which had been burning brightly a moment before, suddenly went out, and the interior of the submarine yawned under his feet like a deep, impenetrable pit.