"Just in time!" he exclaimed. "He is in one of the forward compartments."
He relocked the door, and, seating himself, proceeded to fill his pipe.
"And now," said I, as the train moved out of the station, "perhaps you will explain this little comedy."
"With pleasure," he replied, "if it needs any explanation. But you can hardly have forgotten Mr. James's flattering remarks in his report of the Greek Street incident, clearly giving the impression that the mysterious document was in my possession. When I read that, I knew I must look out for some attempt to recover it, though I hardly expected such promptness. Still, when Mr. Barton called without credentials or appointment, I viewed him with some suspicion. That suspicion deepened when he wanted us both 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.