that the cut in the clothing no longer
coincides with it. There is quite a considerable angle, which is the
measure of the rotation of the blade."

"Yes, it is odd," said Dr. Egerton, "though, as I said, I doubt that it
helps us."

"At present," Thorndyke rejoined dryly, "we are noting the facts."

"Quite so," agreed the other, reddening slightly; "and perhaps we had
better move the body to the bedroom, and make a preliminary inspection
of the wound."

We carried the corpse into the bedroom, and, having examined the wound
without eliciting anything new, covered the remains with a sheet, and
returned to the sitting-room.

"Well, gentlemen," said the inspector, "you have examined the body and
the wound, and you have measured the floor and the furniture, and taken
photographs, and made a plan, but we don't seem much more forward.
Here's a man murdered in his rooms. There is only one entrance to the
flat, and that was bolted on the inside at the time of the murder. The
windows are some forty feet from the ground; there is no rain-pipe near
any of them; they are set flush in the wall, and there isn't a foothold
for a fly on any part of that wall. The grates are modern, and there
isn't room for a good-sized cat to crawl up any of the chimneys. Now,
the question is, How did the murderer get in, and how did he get out
again?"

"Still," said Mr. Marchmont, "the fact is that he did get in, and that
he is not here now; and therefore he must have got out; and therefore it
must have been possible for him to get out. And, further, it must be
possible to discover how he got out."

The inspector smiled sourly, but made no reply.

"The circumstances," said Thorndyke, "appear to have been these: The
deceased seems to have been alone; there is no trace of a second
occupant of the room, and only one half-emptied tumbler on the table. He
was sitting reading when apparently he noticed that the clock had
stopped--at ten minutes to twelve; he laid his book, face downwards, on
the table, and rose to wind the clock, and as he was winding it he met
his death."

"By a stab dealt by a left-handed man, who crept up behind him on
tiptoe," added the inspector.

Thorndyke nodded. "That would seem to be so," he said. "But now let us
call in the porter, and hear what he has to tell us."

The custodian was not difficult to find, being, in fact, engaged at that
moment in a survey of the premises through the slit of the letter-box.

"Do you