Franklin Row was an attractive street of more red brick; here were plane trees, and a great grassy space bordered with railings, in which a throng of primary school children were playing games in pale blue Aertex tops and navy blue shorts, watched by tracksuited teachers. Their happy cries punctuated the sedate quiet otherwise disturbed only by birdsong; no cars passed as Strike strolled down the pavement towards the house of Lady Yvette Bristow, his hands in his pockets.

The wall beside the partly glass door, set at the top of four white stone steps, bore an old-fashioned Bakelite panel of doorbells. Strike checked to see that Lady Yvette Bristow’s name was clearly marked beside Flat E, then retreated to the pavement and stood waiting in the gentle warmth of the day, looking up and down the street.

Ten thirty arrived, but John Bristow did not. The square remained deserted, but for the twenty small children running between hoops and coloured cones beyond the railings.

At ten forty-five, Strike’s mobile vibrated in his pocket. The text was from Robin:

Alison has just called to say that JB is unavoidably detained. He does not want you to speak to his mother without him present.

Strike immediately texted Bristow:

How long are you likely to be detained? Any chance of doing this later today?

He had barely sent the message when the phone began to ring.

‘Yeah, hello?’ said Strike.

‘Oggy?’ came Graham Hardacre’s tinny voice, all the way from Germany. ‘I’ve got the stuff on Agyeman.’

‘Your timing’s uncanny.’ Strike pulled out his notebook. ‘Go on.’

‘He’s Lieutenant Jonah Francis Agyeman, Royal Engineers. Aged twenty-one, unmarried, last tour of duty started eleventh of January. He’s back in June. Next of kin, a mother. No siblings, no kids.’

Strike scribbled it all down in his notebook, with the mobile phone held between jaw and shoulder.

‘I owe you one, Hardy,’ he said, putting the notebook away. ‘Haven’t got a picture, have you?’

‘I could email you one.’

Strike gave Hardacre the office email address, and, after routine enquiries about each other’s lives, and mutual expressions of goodwill, terminated the call.

It was five to eleven. Strike waited, phone in hand, in the peaceful, leafy square, while the gambolling children played with their hoops and their beanbags, and a tiny silver plane drew a thick white line across the periwinkle sky. At last, with a small chirrup clearly audible in the quiet street, Bristow’s texted reply arrived:

No chance today. I’ve been forced to go out to Rye. Maybe tomorrow?

Strike sighed.

‘Sorry, John,’ he muttered, and he climbed the steps and rang Lady Bristow’s doorbell.