“It was an escape route, something entirely private,” Max Sebald mutters as he rummages through a thick folder of old photographs. A boy in a white gown and caftan; a graveyard with tilted headstones; a turn-of-the-century spa: they’re the kind of photographs you’d come across in a junk shop, leafing idly through a box of postcards. Which is more or less where Sebald found them. He had been collecting photographs for years before he began to write, he explains, scouring the shops in the seaside towns of East Anglia, where he’s lived since emigrating from Germany in 1970, for images to put in his books—or rather, to serve as their catalysts. “Not even people in the house knew what I was up to; I’d just retire to my workshop and potter about. I think it was these photographs that eventually got the better of me.”

They had got the better of me, too. In fact they were a large part of the reason I was sitting over a coffee in Sebald’s comfortable, book-lined study in Norwich. I had come on…