“Any of you fellows know the country just south of Bordeaux?” he asked, and, as no one responded, he went on: “I know it a bit, for I have to go through it every year on my trip round the wine exporters. This year a rather queer thing happened when I was about half an hour’s run from Bordeaux; absolutely a trivial thing and of no importance, you understand, but it puzzled me. Maybe some of you could throw some light on it?”

“Proceed, my dear sir, with your trivial narrative,” invited Jelfs, a man sitting at one end of the group. “We shall give it the weighty consideration which it doubtless deserves.”

Jelfs was a stockbroker and the professional wit of the party. He was a good soul, but boring. Merriman took no notice of the interruption.

“It was between five and six in the evening,” he went on, and he told in some detail of his day’s run, culminating in his visit to the sawmill and his discovery of the alteration in the number of the lorry. He gave the facts exactly as they had occurred, with the single exception that he made no mention of his meeting with Madeleine Coburn.

“And what happened?” asked Drake, another of the men, when he had finished.

“Nothing more happened,” Merriman returned. “The manager came and gave me some petrol, and I cleared out. The point is, why should that number plate have been changed?”

Jelfs fixed his eyes on the speaker, and gave the little sidelong nod which indicated to the others that another joke was about to be perpetrated.

“You say,” he asked impressively, “that the lorry was at first 4 and then 3. Are you sure you haven’t made a mistake of 41?”

“How do you mean?”

“I mean that it’s a common enough phenomenon for a No. 4 lorry to change, after lunch, let us say, into No. 44. Are you sure it wasn’t 44?”