Closing the board at the end of my visits, David always palmed one of the pieces, usually the black bishop, which he had identified with me. This was partly to irritate me, and partly to ensure that I played with no one else. While I searched for him I could hear his gentle voice outside the women’s ward, as he gallantly steered one of the old women towards the lavatories. He greeted me cheerily, closing the lavatory door.

“I hope she knows what to do,” he confided. “Most of the time she just stands there, trying to remember her daughter. She calls it her memory box…”

Affable and good-humoured as ever, he surveyed the day-room, looking for something new to tell me. Patients in dressing gowns sat on the leather chairs, talking to their subdued relatives. On the sofa beside us a young woman lay with her knees pulled up to her chin, lost in her deep sleep of largactil. Her open eyes were tilted into their upper lids, as if she were trying to see something inside her skull. At the dispensary hatch a line of patients queued for their thimbles of tranquilliser.

“They’ll bring some tea in a moment.” David leafed through the aviation magazines, and held my arm, glad to see me. His confinement had brought us together. “It’s good of you to come—how are the kids?”

“They’re blooming, passing all their exams. Henry’s built an aircraft for you—the Wright Flyer. Alice and Lucy wanted to come with me.”

“Not a good idea, actually.” David tore at an orange and treated me to a knowing smile. “They can visit you, Jim, when it’s your turn.”

I let this pass and watched another of the older women, wearing nothing but a faded nightdress, carry a vase of daffodils to the window ledge. She held the flowers to the light, introducing them to the sun.

“It’s restful here,” I commented. “All the sunlight, and these sleeping women. You could be in a private hotel on the south coast.”

“Of a rather special kind, dear sport.”

“I know—it always amazes me that they let the men and women wander around together.”

“No one’s got pregnant yet.” David stared at the young woman asleep on the sofa beside him, the hem of her nightdress around her plump calves. As he set out the chessboard I noticed that the black king had failed to appear, a modest penalty I had incurred. “Besides, the medical staff trust us completely. For them, we’re the normal ones. They know our names and faces and little ways of doing things. It’s you people who seem genuinely weird.”

“We probably are.”