“I gather that he has been in an opium den of some kind,” said Tab. “Yeh Ling—”
“The man who owns the Golden Roof?” asked the editor quickly.
“That’s the chap. He gave us a hint that that is where Brown had been staying. The man was a notorious drug fiend.”
“I understand that two men went into the house together. Nobody saw the second man?”
“Nobody except Stott,” said Tab, “and Stott was so scared that he cannot give us anything like a picture of either of them. Certainly nobody saw him come out; he was gone when we arrived.”
“And the key on the table—what does that mean?”
Tab made a gesture of despair.
“Of course I know what it means,” said the editor thoughtfully. “It is the murderer’s defense, prepared with devilish ingenuity in advance. Don’t you realise,” he said, seeing that his junior was taken aback by this theory, “that before you can convict the man who killed Trasmere, and presumably also killed Brown, you would have to prove that it was possible for him to get into the vault and out again, lock the door and return the key to the table—and that is just what you could not prove.”
That the murderer had this in his mind was a new possibility to Tab. He had regarded the appearance of the key as a piece of whimsical mystifying on the part of the murderer, an act of bravado, rather than a serious attempt to save his own neck in the event of his detection.
“Carver says—” he began.