er learned with what murder case it was connected?"

"No--the fact is, it passed pretty much out of my mind, as far as the
details were concerned. Although I'll never forget the picture."

"Pardon me for asking questions. I--I--just happen to come from Boston
and was trying to recall such a case. You don't remember what time of
the year it was, or how long ago?"

"Yes, I do. It was in the summer, along about two or two and a half
years ago."

Houston slumped back into his corner. Ten minutes later, he found an
opportunity to exchange cards with the young physician and sought his
berth. To himself, he could give no reason for establishing the identity
of the smoking-compartment informant. He had acted from some sort of
subconscious compulsion, without reasoning, without knowing why he had
catalogued the information or of what possible use it could be to him.
But once in his berth, the picture continued to rise before him; of a big
room in a hospital, of doctors gathered about, and of a man "killing"
another with a mallet. Had it been Worthington? Worthington, the
tired-eyed, determined, over-zealous district attorney, who, day after
day, had struggled and fought to send him to the penitentiary for life?
Had it been Worthington, striving to reproduce the murder of Tom Langdon
as he evidently had reconstructed it, experimenting with his experts in
the safety of a different city, for points of evidence that would clinch
the case against the accused man beyond all shadow of a doubt?
Instinctively Houston felt that he just had heard an unwritten,
unmentioned phase of his own murder case. Yet--if that had been
Worthington, if those experts had found evidence against him, if the
theories of the district attorney had been verified on that gruesome
night in the "dead ward" of Bellstrand Hospital--

Why had this damning evidence been allowed to sink into oblivion? Why
had it not been used against him?

CHAPTER XVI

It was a problem which Barry Houston, in spite of wakefulness, failed
to solve. Next morning, eager for a repetition of the recital, in the
hope of some forgotten detail, some clue which might lead him to an
absolute decision, he sought the young doctor, only to find that he had
left the train at dawn. A doorway of the past had been opened to
Houston, only to be closed again before he could clearly discern
beyond. He went on to Boston, still struggling to reconstruct it all,
striving to figur