"Do they expect us to back down?" asked the superintendent harshly. "If
Waverley has been fool enough to get himself in a fix, he must take his
chance if we can't get him out. Let's have a look at this paper."

He thrust his hand in a drawer, and, flinging a pinch of black powder on
the letter, sifted it gingerly to and fro. In a few seconds four
finger-prints stared out blackly from the white surface. They were at
right angles to the type, and just beneath it. Foyle's face relaxed in a
pleased smile.

"They've given us something that may help us, after all, Green," he
cried. "Look here; these two middle ones are the prints on the dagger.
Now let's see if we can learn anything from the typing."

Half an hour later three men stood in a tiny room, darkened, save for a
vivid patch of white on a screen a yard and a half square. Foyle and
Green watched the screen intently as the third man inserted the slide in
the powerful magic lantern. Magnified enormously, the typewritten
characters stood out vividly black against the white.

"What do you make of it, Green?" asked the superintendent after a
pause.

"Remington machine, latest pattern," answered the other briefly. "The
letter 'b' slightly battered, and the 'o' out of alignment. Used by a
beginner. There is double spacing between some of the lines and single
in others. A capital 'W' has been superimposed on a small one."

"That's so," agreed his superior thoughtfully. "You might see if the
Remington people can give us any help with that. If possible, get a list
of all the people who have bought machines during this last six weeks.
It's a long shot, but long shots sometimes come off. And if you come
into my room I'll give you a pistol. It'll be as well for you to carry
one while you're on this case. I was shot at myself, to-day."

"Thank you, sir, I think I'll do without one," said the other quietly.
"My two fists are good enough for me."

"As you like," agreed Foyle, and Green departed on his mission. When he
returned, he walked into Foyle's room and laid a long list before his
chief. The superintendent cast his forefinger slowly down it.

"October 14," he read, "Mr. John Smith, c/o Israels, 404A Grave Street,
Whitechapel." He looked up into the stolid face of Green. "That seems
like it," he went on. "You and I will take a little trip this evening,
Green. And I think you'd better have a pistol, after all."

CHAPTER XIV

To all callers, relatives, frie