Thoms was down on his knees, an absurd figure, frantically reaching out to the apparatus. Roberts, who had stooped down to the lower framework of the cruet-like stand and had rapidly inspected it, thrust the little fat man aside. He tested the nuts that held the frame together. His hands shook a little and his face, the only one unmasked, was very pale.

“It’s perfectly secure, Thoms,” he said. “None of the nuts are loose. Matron, please stand away.”

“I didn’t mean—I’m sorry,” began Sister Marigold.

“Do you realise—” said Thoms in a voice that was scarcely recognisable—“do you realise that if one of those cylinders had fallen out and burst, we’d none of us be alive. Do you know that?”

“Nonsense, Thoms,” said Roberts in an unsteady voice. “It’s most unlikely that anything of the sort could occur. It would take more than that to burst a cylinder, I assure you.”

“I’m sure I’m very sorry, Mr. Thoms,” said matron sulkily. “Accidents will happen.”

“Accidents mustn’t happen,” barked Thoms. He squatted down and tested the nuts.

“Please leave it alone, Mr. Thoms,” said Roberts crisply. “I assure you it’s perfectly safe.”

Thoms did not answer. He got to his feet and turned back to the table.

“And now what happens?” asked Alleyn. His deep voice sounded like a tonic note. Phillips spoke quietly.

“I made the incision and carried on with the operation. I found peritonitis and a ruptured abscess of the appendix. I proceeded in the usual way. At this stage, I think, Dr. Roberts began to be uneasy about the pulse and the general condition. Am I right, Roberts?”

“Quite right, sir. I asked for an injection of camphor.”

Without waiting to be told, Nurse Banks went to the side table, took up the ampoule of camphor, went through the pantomime of filling a syringe and returned to the patient.

“I injected it,” she said concisely.

Through Alleyn’s head ran the old jingle: “A made an apple pie, B bit it, C cut it—I injected it,” he added mentally.

“And then?” he asked.

“After completing the operation I asked for the anti-gas serum.”

“I got it,” said Jane bravely.

She walked to the table.

“I stood, hesitating. I felt faint. I—I couldn’t focus things properly.”

“Did anybody notice this?”

“I looked round and saw something was wrong,” said Phillips. “She simply stood there swaying a little.”

“You notice this, Mr. Thoms?”

“Well, I’m afraid, inspector, I rather disgraced myself by kicking up a rumpus. What, nurse? Bit hard on you, what? Didn’t know how the land lay. Too bad, wasn’t it?”

“When you had finished, Nurse Harden brought the large syringe?”

“Yes.”

Jane came back with the syringe on a tray. “Thoms took it,” went the jingle in Alleyn’s head.

“I injected it,” said Thoms.