It took him a while to get there. Delia Fairfax was waiting for him on the doorstep of her home. She looked anxious. ‘I came back from work, and he wasn’t here.’ She was talking even as she led him into the hallway.

‘Isn’t that good?’ Hobbes said. ‘That he’s getting out of the house?’

‘That’s not the problem. He’s out every day, for hours on end.’

‘So then?’

‘You don’t understand. Come on, I’ll show you.’

Delia led the way upstairs and into a small bedroom at the rear of the house. It was a mess, with clothes scattered everywhere, half-eaten plates of food, and screwed-up papers all over the floor. One wall was pinned with newspaper clippings, all relating to the Richmond Park killing. Photographs were pinned up here and there, all taken by Fairfax. They showed the area around the crime scene where Nicholas Graves had been found, including the dead dog with its fungal coating.

Hobbes wiped his face with his handkerchief. His skin was damp.

‘He doesn’t like me coming in here,’ Delia said. ‘Not at all. Forbids me even to give it a quick clean. Can you Adam and Eve it?’

A desk was covered with sheets of notes, all concerned with one thing only, or rather, five things: the objects found in the jewellery box in the cellar of Bridlemere. Fairfax had become obsessed with these, more than with any other part of the case. He must have spent a good few hours in the library. He’d identified the silver medal and ribbon as being a Distinguished Conduct Medal, bestowed for exceptional acts of gallantry during the First World War. The name Leonard Graves? was written alongside this information. The Greta Garbo cigarette card had first been issued in 1934, part of a collection of famous movie stars. Fairfax’s notes wove a complex story, a fantasy, from the items and what they might mean for the mystery girl in the flowered dress, and for the Graves family in general. It wasn’t at all based on reality, but on a kind of fevered dream in the detective’s head. In many ways, Fairfax had conducted the perfect investigation, but one that was utterly useless, based as it was on spurious ideas and imagined connections.

‘I don’t understand.’

‘Neither do I, Inspector. I’ve given up trying to—’

‘No, I mean I don’t understand what Tommy is doing here. He’s trying to solve a current case, but he won’t come into work. It doesn’t make sense.’

‘I’ve told you, he’s a proud man.’

‘His position will be taken over, maybe next week.’

‘You mean he’ll be out of work?’ Delia was stricken by the news.

‘Yes.’

‘He’ll have to … he’ll have to sign on?’

‘Or get a job.’

‘But what would he do? Tommy’s only good at one thing. Being a copper! That’s it.’

Hobbes picked up a set of five photographs, depicting the objects found in the jewellery box. He felt a pang of guilt. Fairfax had worked from these images: his starting point for his own personal investigation. And Hobbes had given the photographs to him. He’d made a mistake. He should never have used the Graves case as a temptation.