wouldn't lie at all."

There was the sound of a motor below, and Tarling walked to the window.

"Here is Ling Chu," he said, and a few minutes later the Chinaman came
noiselessly into the room.

Tarling greeted him with a curt nod, and without any preliminary told the
story of the crime. He spoke in English--he had not employed Chinese
since he discovered that Ling Chu understood English quite as well as he
understood Cantonese, and Whiteside was able from time to time to
interject a word, or correct some little slip on Tarling's part. The
Chinaman listened without comment and when Tarling had finished he made
one of his queer jerky bows and went out of the room.

"Here are the letters," said Whiteside, after the man had gone.

Two neat piles of letters were arranged on Mrs. Rider's desk, and Tarling
drew up a chair.

"This is the lot?" he said.

"Yes," said Whiteside. "I've been searching the house since eight o'clock
and I can find no others. Those on the right are all from Milburgh.
You'll find they're simply signed with an initial--a characteristic of
his--but they bear his town address."

"You've looked through them?" asked Tarling

"Read 'em all," replied the other. "There's nothing at all incriminating
in any of them. They're what I would call bread and butter letters,
dealing with little investments which Milburgh has made in his wife's
name--or rather, in the name of Mrs. Rider. It's easy to see from these
how deeply the poor woman was involved without her knowing that she was
mixing herself up in a great conspiracy."

Tarling assented. One by one he took the letters from their envelopes,
read them and replaced them. He was half-way through the pile when he
stopped and carried a letter to the window.

"Listen to this," he said:

"Forgive the smudge, but I am in an awful hurry, and I have got my
fingers inky through the overturning of an ink bottle."

"Nothing startling in that," said Whiteside with a smile.

"Nothing at all," admitted Tarling. "But it happens that our friend has
left a very good and useful thumb-print. At least, it looks too big for a
finger-print."

"Let me see it," said Whiteside, springing up.

He went to the other's side and looked over his shoulder at the letter in
his hand, and whistled. He turned a glowing face upon Tarling and gripped
his chief by the shoulder.

"We've got him!" he said exultantly. "We've got him as surely as if we
had him in the pen!"