stranger. The man was lying on his back in a state of coma, his breath
came heavily between his parted lips.

Bell bent low partly to examine the patient, partly to hide his face
from Cross. If Bell had made any discovery he kept the fact rigidly
to himself.

"Looks very young," he muttered. "But then he is one of those men who
never grow any hair on their faces. Young as he looks, I should judge him
to be at least forty-five, and, if I am not mistaken, he is a man who has
heard the chimes at midnight or later. I'm quite satisfied."

"It's more than I am," Cross said, when at length he and his visitor were
standing outside together. "Look here, Bell, you're a great friend of
Steel's, whom I believe to be a very good fellow. I don't want to get him
into any harm, but a day or two ago I found this letter in a pocket-book
in a belt worn by our queer patient. Steel says the fellow is a perfect
stranger to him, and I believe that statement. But what about this
letter? I ought to have sent it to the police, but I didn't. Read it."

And Cross proceeded to take a letter from his pocket. It was on thick
paper; the stamped address given was "15, Downend Terrace." There was no
heading, merely the words "Certainly, with pleasure, I shall be home; in
fact, I am home every night till 12.30, and you may call any time up till
then. If you knock quietly on the door I shall hear you.--D.S."

"What do you make of it?" Cross asked.

"It looks as if your patient had called at Steel's house by appointment,"
Bell admitted. "Here is the invitation undoubtedly in Steel's