‘You’re aware that a young man was found dead in the garden of your home,’ Lightman said, sticking to the rule of giving away as little as possible at any given moment.

‘Yeah, but she said it was a stranger,’ Niall said, as he waited for Lightman to use his swipe card on the door of CID. ‘Nobody she knew.’

Lightman glanced at him, able to divine that this was as much a question as it was a statement. Niall Reakes was looking for reassurance, and Lightman would not be giving it to him.

‘We need to clear up a few things with both of you,’ he said, evenly, keeping his expression absolutely neutral. ‘I’m sure the DCI can tell you more as soon as he’s back.’

He opened the door, and was surprised to feel Niall’s hand on his upper arm in a clumsy grab.

‘Please,’ Louise’s husband said in a desperate voice, ‘please tell me if she was screwing someone else. I need to know.’

A narrow garden with a high fence ran from the back door of Alex Plaskitt’s terraced house down to a blue-painted single-storey building at the far end. The green-brown skeletons of climbing plants and a few rhododendrons gave the only signs of life. The rest of the garden looked bleak in the spotlight over the back door. Half-melted snow lay over patches of grass and mud, and the rest showed no sign of disappearing.

‘It’s a lot nicer in daylight, and in summer,’ Issa said, with a note of apology. ‘Alex spent half of last summer out here, either filming or doing … workouts.’ He faltered, his eyes fixed on the widest part of the grass, as if seeing Alex there. His expression was desolate.

‘So that was his studio?’ Jonah asked, gently, nodding towards the building at the end.

‘Yes.’ Issa looked up at it. ‘His gym. I’ve got the key …’

He led Jonah and Hanson to the side of the building, planting his feet carefully on each of the slippery moss-covered stepping stones that meandered down towards it. The door was locked by a simple padlock through a ring with a metal flap. ‘It’s not a real building,’ Issa said, apparently still feeling the need to apologise. ‘We just bought a really big summer house for a grand and a half and assembled it. Alex did most of it on his own.’

Issa leaned in to flick a light switch. Jonah stepped in first, and said, ‘It’s impressive,’ in part to make Issa feel better. But also in part because it was. Along one wall were racks containing stacks of free weights. At the rear were a rowing machine, treadmill and spinning bike. The centre of the space was covered in rubberised matting, and sported two fit-balls of different sizes.