oth to come. It deepened further when I found an
impossible quantity of arsenic in his sample, and it gave place to
certainty when, having allowed him to select the trains by which we were
to travel, I went up to the laboratory and examined the time-table; for
I then found that the last train for London left Rexford ten minutes
after we were due to arrive. Obviously this was a plan to get us both
safely out of the way while he and some of his friends ransacked our
chambers for the missing document."

"I see; and that accounts for his extraordinary anxiety at the lateness
of the train. But why did you come, if you knew it was a 'plant'?"

"My dear fellow," said Thorndyke, "I never miss an interesting
experience if I can help it. There are possibilities in this, too, don't
you see?"

"But supposing his friends have broken into our chambers already?"

"That contingency has been provided for; but I think they will wait for
Mr. Barton--and us."

Our train, being the last one up, stopped at every station, and crawled
slothfully in the intervals, so that it was past eleven o'clock when we
reached Liverpool Street. Here we got out cautiously, and, mingling with
the crowd, followed the unconscious Barton up the platform, through the
barrier, and out into the street. He seemed in no special hurry, for,
after pausing to light a cigar, he set off at an easy pace up New Broad
Street.

Thorndyke hailed a hansom, and, motioning me to enter, directed the
cabman to drive to Clifford's Inn Passage.

"Sit well back," said he, as we rattled away up New Broad Street. "We
shall be passing our gay deceiver presently--in fact, there he is, a
living, walking illustration of the folly of underrating the
intelligence of one's adversary."

At Clifford's Inn Passage we dismissed the cab, and, retiring into the
shadow of the dark, narrow alley, kept an eye on the gate of Inner
Temple Lane. In about twenty minutes we observed our friend approaching
on the south side of Fleet Street. He halted at the gate, plied the
knocker, and after a brief parley with the night-porter vanished through
the wicket. We waited yet five minutes more, and then, having given him
time to get clear of the entrance, we crossed the road.

The porter looked at us with some surprise.

"There's a gentleman just gone down to your chambers, sir," said he. "He
told me you were expecting him."

"Quite right," said Thorndyke, with a dry smile, "I was. Good-night."

We