Fond as he was of his younger sister, he had come to accept that their relationship rested almost entirely on shared and largely traumatic memories. He never confided in Lucy unless forced to do so by external events, for the simple reason that confidences usually elicited alarm or anxiety. Lucy lived in a state of perennial disappointment that he was still, at the age of thirty-seven, holding out against all those things that she believed necessary to make him happy: a job with regular hours, more money, a wife and children.

Glad to have got rid of her, Strike made himself his third mug of tea of the morning and laid back down on the bed with a pile of newspapers. Several of them displayed a photograph of MURDER VICTIM KELSEY PLATT, wearing a navy school uniform, a smile on her plain, pimply face.

Dressed only in boxers, his hairy belly no smaller for the plentiful takeaways and chocolate bars that had filled it in the last fortnight, he munched his way through a packet of Rich Tea biscuits and skimmed several of the stories, but they told him nothing he did not already know, so he turned instead to the anticipatory comment about the next day’s Arsenal–Liverpool match.

His mobile rang while he was reading. He had not realized how tightly wound he was: he reacted so fast that Wardle was taken by surprise.

“Bloody hell, that was quick. What were you doing, sitting on it?”

“What’s going on?”

“We’ve been over to Kelsey’s sister’s place—name’s Hazel, she’s a nurse. We’re looking into all Kelsey’s day-to-day contacts, we’ve gone through her room and we’ve got her laptop. She’d been online, on some message board for people who want to hack bits off themselves, and she was asking about you.”

Strike scratched his dense, curly hair, staring at the ceiling, listening.

“We’ve got personal details for a couple of the people she was interacting with regularly on the boards. I should have pictures by Monday—where will you be?”

“Here, in the office.”

“Her sister’s boyfriend, the ex-fireman, says Kelsey kept asking him about people trapped in buildings and car accidents and all sorts. She really wanted to get rid of that leg.”

“Jesus,” muttered Strike.

After Wardle had hung up, Strike found himself unable to focus on the backroom reshuffles at the Emirates. After a few minutes he abandoned the pretense that he was absorbed in the fate of Arsène Wenger’s management team and resumed his staring at the cracks in the ceiling, absently turning his mobile over and over.

In the blinding relief that the leg had not been Brittany Brockbank’s, he had given less thought to the victim than he would ordinarily have done. Now, for the first time, he wondered about Kelsey and the letter that she had sent him, which he had not bothered to read.

The idea of anybody seeking amputation was repugnant to Strike. Round and round in his hand he turned his mobile, marshaling everything he knew about Kelsey, trying to build a mental picture out of a name and mingled feelings of pity and distaste. She had been sixteen; she had not got on with her sister; she had been studying childcare… Strike reached for his notebook and began to write: Boyfriend at college? Lecturer? She had gone online, asking about him. Why? Where had she got the idea that he, Strike, had amputated his own leg? Or had she evolved a fantasy out of newspaper reports about him?