"Sorry, old chap; don't seem to remember it at all if I ever did—not a dashed glimmer of it left." I yawned. "Never tried to keep any of those college things, you know."

Billings, who had been staring, uttered a rude comment.

"It's not a language, you cuckoo," he snapped; "it's a man. He's a D.S.—distinguished scientist, you know. What's more, he's one of your neighbors, right in this building."

"Don't know him," I said a little stiffly. "What's his club?"

Billings all but gnashed his teeth.

"Club, thunder!" he jerked out impatiently. "Why, man, he's a member of all the great societies of the world—bodies whose rank and exclusiveness put the blink on all the clubs you or I ever saw. Got a string of letters after his name like a universal keyboard, and is the main squeeze, the great scream, among all the scientific push over here and in Europe. Lots of dough, but off his trolley with learning."

"And in this building?" I said wonderingly. "What's he like?"

For a moment I had a thought of Foxy Grandpa, but the janitor had said he did not belong in the building. Besides, Billings' next words removed that clue to the lost pajamas. By Jove, how I did long to ask his advice about them! Once I was on the point of doing so—had devilish narrow escape, in fact—but pulled up on the brink. So deuced hard to remember that anything so delicate and sweet and fetching could be Billings' sister, you know. I had been wondering for an hour whether I had better say anything about my adventure up at Tarrytown—wondered if she would like me to.

"Here, you moon calf, wake up!" Billings' coarse voice brought me back to the present, and I had to blink and pretend I was listening. "I'm telling you about Doozenberry! I say you surely must have seen him—you couldn't miss him in a black cave. Queer-looking old skate, tall as a street lamp and as thin; looks like a long cylinder of black broadcloth. So dignified it hurts him."

I reflected.