Adam saluted, said a few words to the quartermasters and went out with them to the fo'castle. The men off watch were just unstrapping themselves from their bunks. Jake Burchall stepped up. "Do I take up the new watch, Mr. Adam?" "Two hours from now. Look here, Jake, there's something I wish you'd do." "Yes sir." Adam lowered his voice. "Did you hear the report? Fluorine all through this planet. Our ports are glass, and fluorine acts on glass. They're thick, of course, and have layers of plastic, but it will wear them through eventually. We've got to think of something to do about it, and I think I have the answer. Remember compartment eighteen? She'll be flooded. Suppose when you're posting that watch you get into a space suit and slide in there. Don't go outside, but cut loose some of the mica lining around the break. When you get it, you can make some mica sheets for the helmet view-ports of your space suit. Then get into compartment eighteen again, and try it out. I'm no chemical expert, but mica should insulate the view-ports on the helmet, and if it'll do that, it will insulate the view-ports of the whole ship. Report to me privately. I don't want to make a fool of myself if Professor Reuter already has some other scheme worked out." Jake grinned in understanding. "Yes sir. He-he-he. Hope he hasn't." In the chart room, when Adam arrived, he found a small gathering. Perkins, the chemists, was there; so was Professor Reuter, the astronomical man, a couple of assistants, and Captain McCausland, looking extremely grave, thoughtful, but ruffled. "Well, Longworth," he said. "You're just in time to order out the navigation watch and set the course back to Earth." Adam was aghast. "Not really?" "Ask these gentlemen." He indicated the scientists. Professor Reuter cleared his throat, but it was Perkins who spoke. "At least we cannot remain here. The fluorine here will gradually, but certainly, cut through the glass in this ship." * * * * * Adam flushed. He burst out: "But you knew there was fluorine a month ago! Didn't anyone--?" Captain McCausland raised his hand. "Please." Professor Reuter explained. "To tell the truth there was some discussion at that time. I am afraid I must confess myself considerably at fault. Dr. Perkins at that time urged that the expedition return and install quartz ports on the _Goddard_. At that time I judged the temperature would be about what it is, minus 200, and at that figure fluorine would not be present in the liquid portion of the atmosphere, but would exist as a gas, and therefore would not make contact with our ports while diving." "I warned you it would be in solution," remarked Dr. Perkins.