"Hollaby?"

"Yes. I admit that the people behind couldn't have seen whether it was really Sessle or not. But you can't tell me that the man who was playing with him was so hypnotised by the blue coat that he never looked at his face."

"My dear old thing," said Tommy. "That's just the point. Hollaby knew all right. You see, I'm adopting your theory-that Hollaby and his son were the real embezzlers. The murderer's got to be a man who knew Sessle pretty well-knew, for instance, about the servants being always out on a Wednesday, and that his wife was away. And also someone who was able to get an impression of Sessle's latch key. I think Hollaby Junior would fulfill all these requirements. He's about the same age and height as Sessle, and they were both clean shaven men. Doris Evans probably saw several photographs of the murdered man reproduced in the papers, but as you yourself observed-one can just see that it's a man and that's about all."

"Didn't she ever see Hollaby in Court?"

"The son never appeared in the case at all. Why should he? He had no evidence to give. It was old Hollaby, with his irreproachable alibi, who stood in the limelight throughout. Nobody has even bothered to inquire what son was doing that particular evening."

"It all fits in," admitted Tuppence. She paused a minute, and then asked: "Are you going to tell all this to the police?"

"I don't know if they'd listen."

"They'll listen all right," said an unexpected voice behind him.

Tommy swung round to confront Inspector Marriot. The Inspector was sitting at the next table. In front of him was a poached egg.

"Often drop in here to lunch," said Inspector Marriot. "As I was saying, we'll listen all right-in fact I've been listening. I don't mind telling you that we've not been quite satisfied all along over those Porcupine figures. You see, we've had our suspicions of those Hollabys. But nothing to go upon. Too sharp for us. Then this murder came, and that seemed to upset all our ideas. But thanks to you and the lady, sir, we'll confront young Hollaby and Doris Evans and see if she recognizes him. I rather fancy she will. That's a very ingenious idea of yours about the blue coat. I'll see that Blunt's Brilliant Detectives get the credit for it."

"You are a nice man, Inspector Marriot," said Tuppence gratefully.

"We think a lot of you two at the Yard," replied that stolid gentleman. "You'd be surprised. If I may ask you, sir, what's the meaning of that piece of string?"

"Nothing," said Tommy, stuffing it into his pocket. "A bad habit of mine. As to the cheese cake and the milk-I'm on a diet. Nervous dyspepsia. Busy men are always martyrs to it."

"Ah!" said the detective. "I thought perhaps you'd been reading-well, it's of no consequence."

But the Inspector's eyes twinkled.