On the second floor was the billiard-room, with a great English table in the centre of it.

But Kent had at once dashed across to the window, an exclamation on his lips.

"Ha! ha!" he said, "what have we here ?" The Inspector shook his head quietly.

"The window," he said in a monotonous, almost sing-song tone, "has apparently been opened from the outside, the sash being lifted with some kind of a sharp instrument.

The dust on the sill outside has been disturbed as if by a man of extraordinary agility lying on his stomach----Don't bother about that, Mr.Kent.