He pulled off his jacket. The sky was pure blue and his shirt was sticky with sweat. He wiped his brow. It was going to be a long hot day.

* * *

At pretty much the same time as Mullen was cursing his own gullibility, Doreen Rankin was dealing with the post addressed to Mr Paul Atkinson of GenMedSoft, a computer software company which specialised in the provision of software for the dental and medical markets. As his personal assistant and office administrator, she took a proprietorial interest in everything that came in addressed to Mr Atkinson personally or to his company generally. She liked to know what was going on, not just because she was nosy, but because her boss regularly failed to keep her informed of important pieces of information which later boomeranged back to hit her with an almighty thwack.

More and more, the interesting and important letters and documents were coming in via email. This was a source of great frustration to Doreen, who now only got to grips with things when Paul Atkinson went on holiday and reluctantly gave her access to his emails. The paper post this morning seemed no different from usual: letters from the Vale of White Horse District Council and from the company who managed the business park, various circulars which went straight into the recycling bin and three A4 envelopes all containing sales brochures. Or so she thought. The first two were indeed that; one she kept just in case and the other she tossed on top of the circulars. Doreen Rankin had a laser-beam eye for detail and she noticed even before she ripped open the third envelope that it was addressed by hand. That in itself was unusual, but not unprecedented. A charity appeal, an over-qualified student looking for paid work or an internship, a local business offering a special catering deal — these were the potential correspondents that flicked through her mind ever so briefly before she ripped the white envelope open. There was no ‘Private and Confidential’ on it, so it was by her own rules fair enough that she should take charge of it and vet the contents. Paul would almost certainly tell her off for not doing her job if she didn’t. He had told her right at the beginning that he didn’t want to wade through piles of tedious post when he had more important things to do.

Doreen Rankin, who had been standing up as she prepared to give this final piece of correspondence a thumbs up or down, made a mewing sound and sat down very heavily in her chair. She felt giddy with shock and prurient excitement. Then she stood up, went over and shut the door to her small office, closed the blind on her internal window and returned to the desk. There were three photographs and they all told the same story: Paul Atkinson was having an affair. Not that this came as a surprise to Doreen. She had seen his eyes wander when any young women were within his vicinity and his hands too with a female student who’d come in as a temp. She had been skinny as hell, but the woman in the three photographs was anything but. She needed to go on a crash diet. God only knew what Paul saw in her, but Doreen Rankin had long since given up trying to understand men. She slipped the photographs back into the envelope and slid it into her top drawer, which she locked. She needed time to think. What should she do? Give it to Paul and apologise for having opened it, but commit herself to secrecy? Keep it as insurance against the future? Shred it and pretend she had never received it? Paul had a meeting that morning and wasn’t due in the office until after lunch. At least she had some time to think.

* * *

Mullen could have returned the way he had come, up river, but he wanted to buy a bottle of water (why on earth hadn’t he brought one with him?). However, there was another good reason for walking over Donnington Bridge, along Weirs Lane and then up the Abingdon Road again (right past where his car was parked). As he saw it, the only way he could find evidence that Chris’s death was an accident was to prove to Rose and her church friends that Chris had gone back on the booze. Of course they all wanted to believe he was a reformed character who had forsworn alcohol forever. Mullen understood that. He could sympathise with them for wanting it to be so. But life had hardened him. He held to the view that Chris had most likely relapsed and gone on a bender and had fallen in the river as a result. A pile of empties wherever it was that Chris slept would as good as prove it. Or a friend of Chris prepared to exchange the truth for a couple of packs of cigarettes. Or indeed a shopkeeper who could verify that Chris had bought booze from their shop. Or even a pub. However, pubs were a bit of an endangered species these days. The Wagon and Horses had been turned into a Tesco after considerable local resistance, but Mullen knew that there were two or three others still plying their traditional trade along the road into the city centre, so he would visit them.

If he could find just one piece of evidence of Chris’s drinking, that would be quits as far as he was concerned. £300 wasn’t a lot for the job, but it would be fair enough in the circumstances. Rose and her friends couldn’t complain just because the truth was different from what they wanted it to be.

Mullen made his way steadily up the Abingdon Road, armed with his short spiel and the photograph of Chris. It was an unproductive search: none of the pubs remembered serving him, none of the shops admitted to selling him alcohol, though in two cases they certainly recognised him from the photograph. “He smelt a bit, like they all do,” was the first comment. “Came in here from time to time for food or fags, but I can’t say I ever had any problems with him.”

Mullen nearly challenged the man, but decided there wasn’t any point. If that was how the homeless were remembered and judged — whether they were any trouble or not — he couldn’t really blame people. But he felt irritated and protective nevertheless. In his experience the homeless could be kind, supportive and loyal, just like anyone else. And if they smelt a bit, was that any surprise?

The woman behind the till in the next shop recognised the photo immediately. “Yes, a very polite man,” she said. “Always asked me how I was. Not like most people who are in far too much of a hurry.”

“So he was a bit of a regular, was he?”

“Maybe two or three times a week.”

“And did he ever buy alcohol?”

Furrows creased her flawless brown skin as she considered the question. “No, not from me. Mind you, I am not on the till all the time.”

Mullen found himself warming to her: she didn’t want to mislead or pretend certainty if there was any suggestion of doubt — a perfect witness. “Did he ever come into the shop smelling of alcohol?”

She pursed her mouth, but her reply was unequivocal: “No, definitely not.”

Mullen picked up a bar of chocolate from the shelves immediately to his right. “I’ll have this,” he said. It wasn’t exactly a chocolate day; the temperature was mid-seventies at least. But he felt he needed to thank her by buying something.

“He had a very nice voice too,” she said, handing Mullen his change. “Proper Queen’s English.”

The encampment which the rotund Ronnie Corbett-Barker had talked about, before being bullied into silence by the Hells Angel, proved to be easy to find. Once Mullen had reached Folly Bridge, he turned left down the footpath and followed the Thames up-river, winding past modern flats and Victorian terraces, college accommodation and sheltered housing and then suddenly there were grass and trees and bushes on his left. Mullen followed the meandering course of the river, passing under a black iron bridge and soon after that beneath the railway. It was then that he saw the settlement, a ragged line of tents stretching away from the main river alongside a meagre tributary.

Mullen paused. He was feeling queasy. He had already devoured the unnecessarily large chocolate bar, conscious that in this heat, it would cause a mess if he didn’t. But now he was regretting it. He would have been much better off buying a nice wholemeal sandwich from the delicatessen he had passed. He took a swig of water and advanced. As he got closer, he realised the site was much tidier than he had expected. He imagined most of them either kept their belongings inside their tents or carried them with them. It was also pretty much deserted, excepted for a couple of men sitting together in the shade of a bush. They were playing cards.