“It was this way,” Rucker explained. “Last night, after we got the derrick rigged again, I starts and runs the engine for a little while, just to make sure everything is in workin’ order. When I shuts down, I banks the fire under the boiler so it’ll keep overnight. ’Long about sunrise this mornin’ I hikes over to stir her up for business, and when I yanks the fire-box door open, it’s me for throwin’ that fit o’ the jumps. There was the yallerist, cockiest-lookin’ skull you ever see, settin’ on top o’ the banked fire, ready to pull a grin on me when I opens the door.” “A skull?--a human skull?” exclaimed Tregarvon incredulously. “Yep; a yaller one; all teeth and eye-holes, and with a sort of greasy black smoke comin’ out o’ the place where its nose ought to ’a’ been.” “How did it get there?” Carfax asked the question and then answered it himself by adding: “But, of course, you don’t know.” Rucker was wiping his face with a piece of cotton waste--the machinist’s handkerchief. The autumn morning was cool and bracing on the mountain top, yet the perspiration stood in fine little beads on his forehead. “No, I don’t know; and if you was to search me all day, you’d never get it out o’ me where it come from, ’r who put it there,” he said. “I ain’t what you’d call jumpy, but after it was all over, I didn’t want no breakfast.” “What did you do with it?” Tregarvon asked. “Me? I jammed it back into the coals with the clinker hook, and put the blower on, quick! Says I, ‘All right, my bucko! You make me throw a fit, and I’ll make you make steam!’” “Heavens! You burned it?” Tregarvon was still conventional enough to be half horrified, and Carfax shuddered in sympathy. “I certain’y did. But he got back at me, right now! In less ’n five minutes by the watch that old boiler was red-hot and blowin’ off steam to beat the band. She was sweatin’ black smoke at every joint; and when I chases ’round to open the fire-door--Well, you needn’t believe me if you don’t want to, but them grate-bars was drippin’ something ’r other that looked like burnin’ blood!” There is a point beyond which the thread of sympathetic horror snaps, and the ball rebounds into the field of the ridiculous. “That will do for you, Billy,” Tregarvon laughed. “We’ll allow you the skull, but you needn’t embroider it for us. Somebody played a grisly joke on you--with no particular object, that I can see. Just the same, it has its significance. Some prowler was sneaking around here while you were asleep. Are you sure the drill is working all right?” “You can see for yourself,” said Rucker, not unboastfully. “She’s jumpin’ up and down to the old tune of forty to the minute, same as I promised you she’d be this mornin’.”