“Sometimes, though, friends don’t turn up,” Jessica said inconsequently. “If they don’t, mind you come, both of you.”

A few minutes after they had gone a man rowed up rapidly in a dinghy.

“Can I speak to Captain Preston, please?” he asked. “I am his servant. I have just come from his house-boat.”

He had addressed La Planta, who, leaning against the rail, had been watching him approach.

“Is it anything important?” La Planta inquired, eyeing the man coldly.

“It is.”

“Well, Captain Preston and Miss Hagerston have just left. You must have passed them.”

“Have they gone back to the boat?”

“I expect so. They went down stream.”

Borne along the water came the strains of a revue waltz played further down the river by the string quartette.