He stepped out on to the drive, and signalled with his arm. The luggage cart stopped, and after a word or two of explanation Lemoine climbed in behind. He raised his hat politely to Virginia, and drove off.

The other two stood and watched the cart disappearing with puzzled expressions. Just as the cart swung round the bend, a suitcase fell off into the drive. The cart went on.

“Come on,” said Virginia to Bill. “We’re going to see something interesting. That suitcase was thrown out.”

“Nobody’s noticed it,” said Bill.

They ran down the drive towards the fallen piece of luggage. Just as they reached it, Lemoine came round the corner of the bend on foot. He was hot from walking fast.

“I was obliged to descend,” he said pleasantly. “I found that I had left something behind.”

“This?” said Bill, indicating the suitcase.