sir--_awful_!"

"By Jove!" I gasped. "Excuse me--will see--come right back and tell
you--I feared this last night." And I rushed to the elevator with
Jenkins.

"He's in them black pajamas he was talking about," said Jenkins
gloomily, "and he's run the perfesser off. Leastwise, he ain't there,
and his man can't get Mr. Billings to go. He came down for me, but I
couldn't do a thing with him, either."

I knew--I understood. It was the dwelling of his mind upon the rubies!
He had gone back in the night for them--in his sleep, for all I knew.
But I thought most likely awake, for recent experience with him showed
me that he didn't think anything of wandering around the neighborhood in
his pajamas.

The janitor's pale face met us at the landing.

"I've sent for the police, sir, and it would be a good idea, don't you
think, if you could get him away before they come. I don't want to get
Mr. Billings into no trouble."

"Good idea," I agreed. "We'll just rush him to the car--but, h'm!"

I suddenly remembered he was in pajamas. It might be all right to
Billings to wander around in public streets and vehicles in his night
things, but it certainly wouldn't do under the present circumstances.
_He_ might not care, but then, there were the feelings of the girls to
consider. And besides, dash it, I had some sort of idea it was against
the law.

I stood there in the corridor, puzzling.

"We must get his clothes," I said to Jenkins. "No, wait, _wait_--not
time! I want to get him away before the police get here.
Um--dressing-robe--bathrobe--can't you get something of that
sort--quick?"

Jenkins shook his head distractedly.

"Thought of that, sir--no use--nothing anywhere around here would
half-way meet on Mr. Billings."

Here the professor's man interposed.

"Please hurry, sir; he's going through the professor's papers and
things!" I dashed for the apartment, shouting to Jenkins to get a bundle
of rugs and blankets to the car.

Billings was standing by the window looking at a glass thermometer that
he had just withdrawn from his mouth.

"Um!" he grunted complacently. "Ninety-seven and a quarter--my usual
healthy subnormal temperature. Pulse sixty-five--respiration,
twenty-four and two-fifths--excellent, excellent! I am myself. Ha!" And
he whirled triumphantly.

"Ah!" he said, advancing eagerly and rubbing his hands. "It is you! You
have heard, then? Marvelous, isn't it--wholly incredible! But do you
know"--here he p