At 7.20 p.m., the same time that Sara left the Inquiry office, Patrick, having dropped off the hire car in Victoria, approached the front door of a three-storey Victorian house five minutes’ walk from Brixton underground station. After his divorce he’d bought the maisonette on the top two floors as his London home. It was convenient, low maintenance and a neighbourhood he liked – cultured, progressive and fun, a transformation from the riots and roughness of thirty years before that never ceased to amaze him. On his way home he’d been unable, to his irritation, to stop thinking about Sara – it was a long time since he’d enjoyed a woman’s company so much. However hard he tried to discard the image of her smooth skin and shining eyes – and that occasional raised eyebrow – he continued to be thwarted. Taking the front door key out of his pocket, he told himself to wise up.

‘Hey, Patrick!’

A voice nearby. Were they talking to him?

‘Patrick!’ The voice was louder, the accent a hint of Scottish. He turned in the direction it came from. A suited man stood in the half-light on the pavement a few yards to his right; a second man, wearing a blue denim jacket and jeans, muscular, shaven-headed, lounged to his left. There was something familiar about the first man – fair, almost blond, wavy hair, chunky and, yes, the accent. It took just a few seconds for the memory to click in. What was the name? John? John something – he couldn’t remember. Maybe he’d never been given it. Thirteen years were compressed into a split second. It was definitely him – the man who’d hovered in the background while he inked his signature on that piece of paper. The error they’d suckered him into – the greatest single mistake of his life. His heart thumping, he told himself to stay cool.

‘Hello?’ asked Patrick.

‘Yes, hello.’ The Scottish accent was more pronounced.

‘I’m sorry, do I know you?’

‘Oh, come on, Patrick, you remember.’

‘I’m very sorry,’ Patrick replied, straining for politeness despite his agitation, ‘I’m afraid I don’t.’

‘It’ll come to you, laddie.’

Patrick made to slot the key into his front door. The shaven-headed man was beside him before he’d even raised it to the lock.

‘I just wanted to say hello,’ said the first man, coming closer. ‘For old times’ sake.’

‘I truly don’t know what you’re on about.’

‘We won’t worry about that. It’s OK, we’re keeping an eye out. Watching your back.’

‘If you don’t mind, I’d prefer you to leave me alone.’

‘Yes, of course,’ he said cheerfully. He nodded to the second man. Patrick felt a precise, savage finger punch into his kidneys.

‘Jesus!’ he couldn’t help crying out.