Then quite suddenly they were aware that the door had been flung open and that Arthur Surbonadier was standing in the room. With one hand he held on to the door — with the other he fumbled at the spotted neckerchief below his scrubby beard. His mouth was half open and he seemed to be short of breath. At last he spoke.

“Quite a jolly little party,” he said. His voice was thick and they saw how his lips trembled. They stopped short in their laughter, Gardener still with his hand on that lovely shoulder, Stephanie Vaughan open-mouthed and frozen into immobility — rather as though they were posing for a theatrical photograph. There was a quite appalling little silence.

“Charming picture,” said Surbonadier. “All loving and bright. Mayn’t I know the joke?”

“The joke,” said Alleyn quickly, “was a bad one — of mine.”

“The cream of the jest,” said Surbonadier, “is on me. Stephanie will explain it to you. You’re the detective, aren’t you?”

Gardener and Nigel both started talking. Nigel heard himself introduce Alleyn. Gardener was saying something about his supper-party. Alleyn had got to his feet and was offering Miss Vaughan a cigarette. She took it without moving her gaze off Surbonadier, and Alleyn lit it for her.

“I’m sure we ought to go round to the front,” he said. “Don’t let’s miss the first scene, Nigel — I can’t bear to be late.”

He took Nigel by the arm, said something courteous to Miss Vaughan, shook Gardener’s hand, and propelled Nigel towards the door.

“Don’t let me drive you away,” said Surbonadier, without moving from the doorway. “I’ve come to see the fun. Came to see Gardener really, and found him — having his fun.”

“Arthur!” Stephanie Vaughan spoke for the first time.

“Well,” said Surbonadier loudly, “I’ve made up my mind to stop the fun — see? No reason why you shouldn’t hear”— he turned slightly towards Nigel. “You’re a journalist. Literary man. Here’s a surprise — Gardener’s a literary man, too.”