I turned off the motorway. In the distance, across the empty fields, you could already see the black towers of Potter’s Field.

The boy was small for his age and he wore a Potter’s Field school blazer over his fencing whites. He sat on the steps of the main building, pushing back his mop of dark hair as he stared at the paperback in his hands.

‘Any good?’ Ben King said.

The boy looked up, startled. ‘Sir?’

‘Book any good?’

King held out his hand and the boy passed him the paperback, standing up as he did so, self-consciously smoothing his green and purple blazer.

‘The Seven Pillars of Wisdom by T. E. Lawrence,’ King said. He opened it up and read, as if to himself. ‘“But at last Dahoum drew me: ‘Come and smell the very sweetest scent of all,’ and we went into the main lodging, to the gaping window sockets of its eastern face, and there drank with open mouths of the effortless, empty, eddyless wind of the desert, throbbing past.” I read this one when I was your age. How you getting on with it?’

‘Just started it, sir. Pretty good stuff, sir.’

King nodded at him. ‘Waiting to see the Master?’

‘Sir.’

‘Private lesson today?’

A red flush flooded the boy’s pale face. ‘Yes, sir. Every Saturday morning this half. Immediately after fencing club.’

King handed the boy his book. ‘Lesson’s cancelled.’

‘Sir?’

‘Go back to your house. Practise your lunge and parry. Do your prep. Write to your mother.’

The boy looked doubtful.

King clapped his hands once. ‘Go on then!’

The boy went, and we climbed the stairs to the Head Master’s rooms.

Peregrine Waugh answered the door in a plain white kimono. His bliss-heavy eyes took a moment to focus. A smile leapt to his face at the sight of Ben King and died when he saw me.

‘Ah,’ he said.

We followed him inside. Heavy brocade curtains, pulled shut at noon. A thick fug of smoke from whatever had been in the water pipe that sat unlit on an oak desk. Piles of books everywhere.

‘To what do I owe—’

‘Actually we’ve come here for the truth, Perry,’ King told him. ‘Finally.’

I couldn’t breathe in this place. I pulled back the curtains, opened the windows as wide as they would go. On the playing fields, there was the First XV playing rugby against another school watched by a scattering of pupils and two sports masters, and more boys in bright training bibs carrying cones and five-a-side nets to the football pitch. Their shouts and laughter drifted up to me.

‘The truth? You wouldn’t dare! Think of your career, Benjamin. The Right Honourable Member for . . . what’s the name of that dreary little suburb you represent? It’s slipped my mind.’

‘Hillingdon North,’ King said.