t. His intelligent eyes opened slightly.
"Whose is the revolver, Mr. Trent?" he asked in a conversational tone.

"Evidently it belongs to the occupant of the room, Mr. Marlowe," replied
Trent with similar lightness, pointing to the initials. "I found this
lying about on the mantel-piece. It seems a handy little pistol to me,
and it has been very carefully cleaned, I should say, since the last
time it was used. But I know little about firearms."

"Well, I know a good deal," rejoined the inspector quietly, taking the
revolver from Trent's outstretched hand. "It's a bit of a specialty with
me, is firearms, as I think you know, Mr. Trent. But it don't require an
expert to tell one thing." He replaced the revolver in its case on the
mantel-shelf, took out one of the cartridges, and laid it on the
spacious palm of one hand; then, taking a small object from his
waistcoat pocket, he laid it beside the cartridge. It was a little
leaden bullet, slightly battered about the nose, and having upon it some
bright new scratches.

"Is that _the_ one?" Trent murmured as he bent over the inspector's
hand.

"That's him," replied Mr. Murch. "Lodged in the bone at the back of the
skull. Dr. Stock got it out within the last hour, and handed it to the
local officer, who has just sent it on to me. These bright scratches you
see, were made by the doctor's instruments. These other marks were made
by the rifling of the barrel--a barrel like this one." He tapped the
revolver. "Same make, same caliber."

With the pistol in its case between them, Trent and the inspector looked
into each other's eyes for some moments. Trent was the first to speak.
"This mystery is all wrong," he observed. "It is insanity. The symptoms
of mania are very marked. Let us see how we stand. We were not in any
doubt, I believe, about Manderson having despatched Marlowe in the car
to Southampton, or about Marlowe having gone, returning late last night,
many hours after the murder was committed."

"There _is_ no doubt whatever about all that," said Mr. Murch, with a
slight emphasis on the verb.

"And now," pursued Trent, "we are invited by this polished and
insinuating firearm to believe the following line of propositions: that
Marlowe never went to Southampton; that he returned to the house in the
night; that he somehow, without waking Mrs. Manderson or anybody else,
got Manderson to get up, dress himself, and go out into the grounds;
that he then and there shot the s