He was one of those men who are little changed by the passage of time: he might have been twenty-five or thirty-five. Studying him very closely—which few took the trouble to do—one gathered that the latter age was more probably right. He was fair, round-faced, pink-and-white.

“He was quite tame,” said Patricia. “In fact, I thought he was awfully nice. But he would keep on talking about the terrifying things that he thought were going to happen. He said people were trying to murder him.”

Dementia persecutoria,” opined Algy. “What?”

The girl shook her head.

“He was as sane as anyone I’ve ever met.”

Extensio cruris paranoia?” suggested Algy sagely.

“What on earth’s that?” she asked.

“An irresistible desire to pull legs.”

Patricia frowned.

“You’ll be thinking I’m crazy next,” she said. “But somehow you can’t help believing him. It’s as if he were daring you to take him seriously.”