ette Rider to an interview
before the Assistant Commissioner. Whiteside was at Scotland Yard before
him, and when Tarling walked into his room was curiously examining an
object which lay before him on a sheet of paper. It was a short-barrelled
automatic pistol.

"Hullo!" he said, interested. "Is that the gun that killed Thornton
Lyne?"

"That's the weapon," said the cheerful Whiteside. "An ugly-looking brute,
isn't it?"

"Where did you say it was discovered?"

"At the bottom of the girl's work-basket."

"This has a familiar look to me," said Tarling, lifting the instrument
from the table. "By-the-way, is the cartridge still in the chamber?"

Whiteside shook his head.

"No, I removed it," he said. "I've taken the magazine out too."

"I suppose you've sent out the description and the number to all the
gunsmiths?"

Whiteside nodded.

"Not that it's likely to be of much use," he said. "This is an
American-made pistol, and unless it happens to have been sold in England
there is precious little chance of our discovering its owner."

Tarling was looking at the weapon, turning it over and over in his hand.
Presently he looked at the butt and uttered an exclamation. Following
the direction of his eyes, Whiteside saw two deep furrows running
diagonally across the grip.

"What are they?" he asked.

"They look like two bullets fired at the holder of the revolver some
years ago, which missed him but caught the butt."

Whiteside laughed.

"Is that a piece of your deduction, Mr. Tarling?" he asked.

"No," said Tarling, "that is a bit of fact. That pistol is my own!"

CHAPTER XVI

THE HEIR

"_Your_ pistol?" said Whiteside incredulously, "my dear good chap, you
are mad! How could it be your pistol?"

"It is nevertheless my pistol," said Tarling quietly. "I recognised it
the moment I saw it on your desk, and thought there must be some mistake.
These furrows prove that there is no mistake at all. It has been one of
my most faithful friends, and I carried it with me in China for six
years."

Whiteside gasped.

"And you mean to tell me," he demanded, "that Thornton Lyne was killed
with your pistol?"

Tarling nodded.

"It is an amazing but bewildering fact," he said. "That is undoubtedly
my pistol, and it is the same that was found in Miss Rider's room at
Carrymore Mansions, and I have not the slightest doubt in my mind that it
was by a shot fired from this weapon that Thornton Lyne lost his life."