“I haven’t the least idea what you’re driving at, Angela,” complained Nigel. “I should like to hear more about the funny little man. Didn’t he behave at all queerly?”

“He behaved very queerly indeed,” said Alleyn. “He was as scary as a rabbit whenever the murder was mentioned. He’s obviously very frightened whenever he thinks of it. And yet I don’t think his alarm is purely selfish. He said it was, I believe. Thoms, in that asinine way of his, made very merry over Roberts’s alarm when he rang up.”

Alleyn looked steadily at Angela.

“Roberts is the man, depend upon it,” pronounced Nigel. “I’ll back him with you for a quid.”

“I won’t,” said Angela. “I’ll back—”

“I’m afraid the official conscience won’t allow me to join in this cold-blooded gamble,” said Alleyn. He looked at them both curiously. “The attitude of the intelligent layman is very rum,” he observed.

“I lay you two to one the field, bar Roberts, Angela,” said Nigel.

“Done,” said Angela. “In guineas,” she added grandly. “And what were you saying, inspector?”

“I was only reflecting. Does the decision rest with the judge?”

“What do you mean?”

“Well—if it does, you are betting on a man or woman who, if you’re right, will presumably be hanged. I can’t imagine you doing this over any other form of death. That’s what I mean about the attitude of the layman.”

Angela turned red.

“That’s the second time in our acquaintanceship you’ve made me feel a pig,” she said. “The first was because I was too sensitive. The bet’s off, Nigel.”

“You can be pretty cold-blooded yourself, Alleyn,” said Nigel indignantly.

“Oh, yes,” said Alleyn, “but I’m an official.”

“Anyway,” argued Angela, “I was betting on Dr. Roberts’s innocence.”

“So you were.”

“And, anyway,” said Nigel, “I think he did it.”

“How?”

“Er—well—somehow. With an injection.”

“He gave no injections.”

“Who could have done it?” asked Angela. “I mean who had the opportunity?”

“Phillips, who prepared and gave an injection. The special, who was alone with the patient. Ruth, ditto. Banks, who prepared and gave an injection. Thoms gave an injection, but did not prepare it. He was alone in the theatre for a few minutes if Phillips and the matron are telling the truth. He used the big syringe, and as he quite frankly pointed out, he could hardly have palmed another. Jane Harden had time to empty it and refill with hyoscine.”

“Which of them do you say were alone in the theatre before the operation?”

“All the nurses, Thoms and Phillips had the chance to be there, I suppose.”

“Not Roberts?” asked Nigel.

“I think not. He went straight to the anæsthetic-room, where he was joined by the special with the patient.”