That gaunt phantom of doubt gradually closed in upon me. I resolved to fight it, but its very intangibility baffled my efforts to throw it off. When I struck, it was not there. When I gripped it, my fingers closed on space. When I challenged Jean's whole-heartedness she burst into tears and asked what proof she could give that she had not given. And it was because she burst into tears that the phantom stalked me all the closer. Had she laughed and called me a silly boy I would have believed her. Nothing came of it, however, and the days wore on until one forenoon we saw Spoof's tall figure looming up across the snow-waste that lay between Fourteen and Two. As he came up he threw off a miniature cloud of steam in the cold air, reminding me strikingly of Thomson's speech about the steam engine. "A steam engine," Thomson had declared, "is the most human of all inventions. In fact, it's a mechanical man, or, if you put it the other way, man is a human steam engine. Each of them consumes food and converts it into energy. You feed a man beef, and he gives you power. You feed this engine straw, and it gives you power; the same thing, by a slightly different process." "Slightly!" exclaimed the farmer for whom we were working at the time. "Slightly! Do you know the difference between the price of beef and the price of straw?" "Then the engine wins," said Thomson, who would never grant a point in his defense of steam. For some reason this flitted through my mind as Spoof drew up, trailing behind him a cloud of steam like a comet's tail. Spoof was healthy and strong and his engines were functioning properly. We made him welcome, but he would not sit down. "Sorry, but I can't stay," he explained. "Jake is in a bit of a mess. Just came over to Two to tell me about it. It seems the cogitation nut on his base burner--you know the big coal stove Jake puts on so many airs about--bless me if I know what a cogitation nut is; rummy old name, don't you think?--but at any rate it has come loose so Jake posted over to borrow a left-hand monkey wrench with which to tighten it. It seems he can't get at it with an ordinary monkey wrench; must have a left-hand one. I hadn't such a thing about the place, and of course I told him so. "'Danged unfortunate,' says Jake--excuse the adjective, ladies--and he stuck out his chin and massaged it in a way that showed he was worried more than he admitted. "'It will be all right, won't it?' said I, trying to buck him up, and really knowing nothing about it. "'Well, it may be, and it may not be,' said he. 'If we're lucky nothing will come of it.' "'And in case you're unlucky?' I queried. "'Then the bottom will fall out of the stove and the shack will burn down--maybe before I get back. We can't leave it without a fire in this weather, you know.'