Desperate to remove Leandro from Oxford, Dyer went home and spent the morning making plans for the exeat. He was not going to let his son out of his sight. He had taken him to school, and was there waiting for him when the bell sounded, signalling the end of lessons.

The first moments inside the gate were like the first moments in the favela. Dyer noted the activity, of which he was always on the edge, the boys and girls flowing out of their classrooms. The playground acted as a sound-box. Shouts reached his ears, then words – about teachers, prep, games, bun-break. They were exchanges that Dyer knew by heart, like lines from the Phoenix Book of Verse. He was formed in this echo chamber, now it had received him back.

On this Thursday afternoon, he felt that he was walking into a dream. He saw it and he did not see it. Time passed in a strange way. He noticed details that he never normally recognised, alert to see if whoever had taken the false post-it note had swallowed the lure – and therefore had no need to harass Dyer further about it.

The head girl was pulling the rope. On the roof of the Rink, the bell rang, ding dong.

Dyer cast his eyes about for his son. He couldn’t pick him out, and then the crowd thinned, and he saw Leandro standing beside a boy in his class. They were talking to an adult, who lifted his head at Dyer’s approach: a lean Asian man in an ochre suit, with the chiselled features of a minor actor.

‘Who’s that?’ taking Leandro by the hand. He glanced back. Something about that face. In a dashboard light.

‘Oh, that’s Hui’s bodyguard.’

Hui was Chinese, a plump, polite boy with the slightly glazed look of someone who is good at maths. Leandro had once brought him back to St Barnabas Street.

‘Hui’s invited me to go paintballing.’

‘When?’

‘Tomorrow.’

‘Well, that’s too bad,’ Dyer said in a firm voice. ‘I’ve made other plans.’ He had a sudden, chest-tightening recollection that Hui’s father worked for a telecoms giant in Beijing.

Leandro climbs into the car and says nothing until Dyer turns right on Bardwell Road.

‘Why are you going this way?’

‘I was trying a shortcut to see whether this is quicker.’ And to shake off the white Renault Clio that might have been tailing them.

He turns left into St Margaret’s Road, and the car shoots past.

His shortcut brings them out near Jamaica Road. Dyer slows down behind a bus. He puts the car into neutral, waiting for the passengers to board, and glances over at Leandro.

Beside him, his son looks as lost as a dog that runs after birds.

‘What?’ says Dyer.