"It's ingenious, Fox," said Alleyn, "but I don't think it's quite right. I take it, this stage-white dries like a particularly clinging powder. Now if Saint had got it on his glove, earlier in the evening, it would be dry when the glove was used for the cartridges, and if any came off, it would be powdery and not likely to stick to the brass. Through the lens those marks looked as if the stuff had been smeared on, wet."

"The same thing applies to Felix," ventured Nigel. "According to Miss Vaughan, he left her room soon after we did, and after that they only met in his room."

Alleyn swung round slowly.

"That's quite true," he said; "leaving her room vacant, during the black-out."

"I get you," said Fox heavily.

"I don't," confessed Nigel.

"Don't you? Well. I'm jolly well going to be inscrutable. The next thing to do is to see Mr. Jacob Saint again. He said he might call in. Do you know, I believe I'll ask the old darling. Run and do your job, Bathgate."

"Oh, I say," Nigel protested. "Can't I wait and hear Uncle Jacob?"

"Away you go!"

Nigel attempted persuasion and was cheerfully invited to get out before he was thrown out. He departed, conscious of smiles on the faces of Inspector Fox and Detective-Sergeant Bailey. A hunt through the file in his own office rewarded him with a complete account of the Jacob Saint libel action, and the discovery of the reporter's name. He was one Edward Wakeford, whom Nigel knew slightly and who was now literary editor on the staff of a weekly paper. Nigel rang him up and arranged a meeting in the bar of a Fleet Street tavern much patronised by Pressmen. They forgathered at eleven o'clock, and over enormous tankards of lager the subject of the trial was broached.

"You doing this Unicorn murder?" asked Wakeford.

"Yes, I am. I know Alleyn, of the Yard, and was with him at the show. It was a marvellous chance, but, of course, I have to play fair. He vets everything."

"By George, he's a marvel, that man," said Wakeford; "I could tell you of a case"—and did.

"It was Alleyn who asked me to look you up," Nigel told him. "He wants to know if you've any idea who wrote the article in the 'Mex' in the Saint libel action. The story that was supposed to be yours."

Wakeford's reply was startling. "I've always thought it was Arthur Surbonadier," he said.

"Gosh, Wakeford—this—this is simply terrific, honestly it is! Why did you think so?"

"Oh, I've nothing much to go on, but I knew the blighter and I'd written to him, so he could have forged my signature. He was Saint's nephew and likely enough to have inside information."

"But why would he do it? Old Saint paid for his education, and gave him everything he had."