Never more had the identical galleries beneath the dome reminded him of one of Borges’s infinite libraries. A story came back to Dyer of a librarian in dark glasses who had grown blind looking for God in one of the letters on one of the pages of one of the four hundred thousand volumes.

Of course, anyone could come in and search the stacks, but they would have to know what title they were looking for.

Surreptitiously, before sliding the note inside, Dyer opened a volume lower down on his pile; a calf-bound facsimile of manuscripts written by seven eyewitnesses who had accompanied the admiral in charge of the Portuguese fleet, Pedro Álvares Cabral, on his voyage to Brazil.

Dyer had no difficulty in reserving this for a further week.

He was passing the front counter on his way out, having left both books in the stacks, when he caught the librarian’s eye, and stopped to ask if she might check the availability of one other title.

She called it up, seeing his face. ‘J. W. Dyer, did you say? Here we are. A Social and Cultural History of the Lower Amazon Basin.’

His shoes on the grey stone steps have the sound of someone in an empty hall slowly clapping. He hadn’t grasped how on edge he has been since returning from Browsholme, uncertain if Gilles had swallowed his denial. What the librarian tells him: no one is swallowing it.

Lips pressed tightly: ‘I’m sorry, that’s also been requested.’

Jolted by the anonymous requests, all Dyer’s fears writhe up like maggots in a bait tin. He walks down the stairs as if each step is taking him nearer to an incomprehensible menace.

Leaving the Taylorian behind him, Dyer made his way up St Giles. As if carried there by an invisible thread, he crossed Parks Road into Norham Gardens and turned right, into Ward Road, past the Asselins’ imposing house, to the end of the street, and unlatched the low wooden gate to number 8, and rang the doorbell. Once again, no answer. He peered through the curtained front window. Where was she?

Three-forty. Leandro would be at a football training session. Dyer had promised to collect him at six.

On the way to the Co-op to buy dinner, Dyer stopped off in a cocktail bar to taste the cachaça in a bad caipirinha. Barico was the place’s name. He had never noticed it before. He recognised the barman from his stall in the Broad: it was the purveyor of panama hats.