‘The bags have got detachable linings. Bizarre idea, isn’t it? Hidden under the lining of the white bag was a will, handwritten by Lula on your mother’s blue notepaper, and witnessed by Rochelle Onifade. I’ve given it to the police.’

Bristow’s mouth fell open. For several seconds he seemed unable to speak. Finally he whispered:

‘But… what did it say?’

‘That she was leaving everything, her entire estate, to her brother, Lieutenant Jonah Agyeman of the Royal Engineers.’

‘Jonah… who?’

‘Go and look on the computer monitor outside. You’ll find a picture there.’

Bristow got up and moved like a sleepwalker towards the computer in the next room. Strike watched the screen illuminate as Bristow shifted the mouse. Agyeman’s handsome face shone out of the monitor, with his sardonic smile, pristine in his dress uniform.

‘Oh my God,’ said Bristow.

He returned to Strike and lowered himself back into the chair, gaping at the detective.

‘I – I can’t believe it.’

‘That’s the man who was on the CCTV footage,’ said Strike, ‘running away from the scene the night that Lula died. He was staying in Clerkenwell with his widowed mother while he was on leave. That’s why he was hotfooting it along Theobalds Road twenty minutes later. He was heading home.’

Bristow drew breath in a loud gasp.

‘They all said I was deluded,’ he almost shouted. ‘But I wasn’t bloody deluded at all!’

‘No, John, you weren’t deluded,’ said Strike. ‘Not deluded. More like bat-shit insane.’

Through the shaded window came the sounds of London, alive at all hours, rumbling and growling, part man, part machine. There was no noise inside the room but Bristow’s ragged breathing.

‘Excuse me?’ he said, ludicrously polite. ‘What did you call me?’

Strike smiled.

‘I said you’re bat-shit insane. You killed your sister, got away with it, and then asked me to reinvestigate her death.’

‘You – you cannot be serious.’

‘Oh yeah, I can. It’s been obvious to me from the start that the person who benefits most from Lula’s death is you, John. Ten million quid, once your mother gives up the ghost. Not to be sniffed at, is it? Especially as I don’t think you’ve got much more than your salary, however much you bang on about your trust fund. Albris shares are hardly worth the paper they’re written on these days, are they?’

Bristow gaped at him for several long moments; then, sitting up a little straighter, he glanced at the camp bed propped in the corner.

‘Coming from a virtual down-and-out who sleeps in his office, I find that a laughable assertion.’ Bristow’s voice was calm and derisory, but his breathing was abnormally fast.