“Good morning, sir,” he said. “I’m afraid I’ve kept you waiting.” He hung up his hat, pulled off his gloves and sat down at his desk. Phillips watched him without speaking. Alleyn unlocked the desk and then turned towards his visitor.

“What is it you want to tell me, Sir John?”

“I’ve come to make a statement. I’ll write it down afterwards if you like. Sign it. That’s what you have to do, isn’t it?”

“Suppose I hear what it’s all about first,” suggested Alleyn.

“Ever since you went away yesterday I’ve been thinking about this case. It seems to me I must be suspected of the murder. It seems to me things look very black for me. You know what I wrote to O’Callaghan. You know I injected a lethal drug. I showed you the tablets—analysis will prove they only contain the normal dosage, but I can’t prove the one I gave was the same as the ones you analysed. I can’t prove I only gave one tablet. Can I?”

“So far as I know, you can’t.”

“I’ve thought of all that. I didn’t kill O’Callaghan. I threatened to kill him. You’ve seen Thoms. Thoms is a decent little ass, but I can see he thinks you suspect me. He’s probably told you I used a lot of water for the injection and then bit his head off because he said so. So I did. He drove me nearly crazy with his bloody facetiousness. Jane—Nurse Harden—told me what you’d said to her. You know a hell of a lot—I can see that. You possibly know what I’m going to tell you. I want her to marry me. She won’t, because of the other business with O’Callaghan. I think she believes I killed him. I think she was afraid at the time. That’s why she was so upset, why she hesitated over the serum, why she fainted. She was afraid I’d kill O’Callaghan. She heard Thoms tell me about that play. D’you know about the play?”

“Thoms mentioned that you discussed it.”