"Aw, hell, buddy," snarled Alleyn. "C'm on in."

Once in his room he took out a file, opened it, and laid beside it the paper he had taken from Saint, and the one Props had left at the Yard.

"What's that?" asked Nigel.

"With your passion for the word I think you would call it a dossier. It's the file of the Unicorn murder."

"And you're going to add those fresh documents?" Nigel strolled up to the desk.

"Can you read from there?" asked Alleyn anxiously. "Or shall I put them closer?"

Nigel was silent.

"The Saint exhibit is a second letter from Mortlake that lands St. Jacob with a crash at the bottom of his ladder. The note from Props——" Alleyn paused.

"Well?"

"Oh, there you are."

Nigel read the following message, written in rather babyish characters:

"I know who done it and you got the wrong man. J. Saint never done it you did not ought to of arested an innocent man yrs respectfully A. Hickson."

"What's it mean?" asked Nigel.

"It means Props will shortly pay a call on the murderer," said Alleyn.

CHAPTER NINETEEN

Nigel Warned Off

"NOW, DON'T START badgering me with questions," begged Alleyn. "If you must stay, stay quiet. I've got work to do." He pressed his bell, hung up his hat, and lit a cigarette. Then he took off the receiver of his telephone.

"Give me Inspector Boys. Hullo, is that you, Boys? Who's shadowing that fellow Hickson? Oh, Thompson, is it? When is he relieved? That's in about a quarter of an hour. Has he rung up? He has! Where is he? I see. Thank you very much."

To the constable who answered the bell he said: "Ask the man who saw Hickson to come and speak to me."

The man in question appeared in remarkably short time. He stood to attention like a private soldier. Nigel was reminded of Props.

"What's your name?" Alleyn asked.

"Naseby, sir."

"Well, Naseby, I've got a job for you. You know Thompson?"

"Yes, sir."