He wore thick-soled shoes — serviceable shoes, country shoes — and he balanced them on their outer edges as he dangled his hands between his knees. After a moment, he ran one hand through thinning hair that was the slow-greying colour of soot. It didn’t seem so much a gesture of seeing to his appearance as it did one of rumination. His face, raised to study the da Vinci, looked both worried and pained, with crescent bags beneath his eyes and heavy lines on his brow.

He pressed his lips together. The lower one was full, the upper one thin. They formed a seam of sorrow on his face, and they seemed to be acting as inadequate containment for an inner turmoil. Fellow struggler, Deborah thought. She was touched by his suffering.

“It’s a lovely drawing, isn’t it?” She spoke in the sort of hushed whisper one automatically uses in places of prayer or meditation. “I’d never seen it before today.”

He turned to her. He was swarthy, older than he had seemed at first. He looked surprised to have been spoken to out of the blue by a stranger. “Nor I,” he said.

“It’s awful of me when you think that I’ve lived in London for the last eighteen years. It makes me wonder what else I’ve been missing.”

“Joseph,” he said.

“Sorry?”

He used the museum plan to gesture at the cartoon. “You’re missing Joseph. But you’ll always be missing him. Haven’t you noticed? Isn’t it always Madonna and Child?”

Deborah glanced again at the artwork. “I’d never thought of that, actually.”

“Or Virgin and Child. Or Mother and Child. Or Adoration of the Magi with a cow and an ass and an angel or two. But you rarely see Joseph. Have you never wondered why?”

“Perhaps…well, of course, he wasn’t really the father, was he?”

The man’s eyes closed. “Jesus God,” he replied.

He seemed so struck that Deborah hurried on. “I mean, we’re taught to believe he wasn’t the father.