Elvira Hart loved living on Ash Island. She had bought a houseboat there years ago when she retired. The 260-yard-long teardrop-shaped mound was largely wooded, unlike its immediate upstream neighbour Tagg’s. She prized its seclusion. The only access was by boat or along the footpath along the top of the East Molesey weir to the southern bank. Unlike Tagg’s, there were few homes on Ash apart from the houseboats. It was a close-knit community and the only significant business there was a small boatyard on the southern shore.

Ash Island was usually a peaceful place, but last night had been different. The party on Tagg’s she had been to earlier was still continuing, loud conversation and music drifting down. It was too hot to sleep inside the houseboat and she had considered sleeping on the deck. It was something she often did in the summer heat, lying naked on a beach lounger, with just a sarong over her to keep the midges away. But last night there had still been too much racket. She had decided instead to take a short run. Across the weir, along Hurst Meadows park to Walton and back again. She hoped it would restore her equilibrium.

If only she had known what she was to discover. She would have stayed at home.

It was four a.m. when she saw it. Just after dawn. She had stopped running at the weir, walking over to avoid generating a metallic thrum on the walkway that might wake others in their houseboats. She saw something bobbing between two of the boats. Going over to take a closer look, she did a double-take. And then screamed like she had never screamed before.

It was a body, a swollen purple-faced horror, with bulging bloodshot eyes staring back at her. It resembled nothing so much as a medieval demon. That it was a man, naked and dead, was in no doubt. She couldn’t imagine what had happened to him.

Stumbling backwards, she fell against a fence. Reached for her phone and, fingers trembling, tapped out three nines.

Chapter Three

There were several more calls in the next hour, from those whose homes backed onto the river. Surrey police were soon on the scene, the islands taped off, uniformed officers assembling by a van, getting ready to fan out for door-to-door. Standing away from the senior officers, PCs Jim Cottesloe and Andrew Wickens stood on the Tagg’s Island bridge, now blocked by their patrol car, and awaited a fire service recovery boat.

‘Looks like a lovely day to kill yourself,’ Cottesloe said, squinting into the sunrise. He was a thick-set fifty-year-old with a shaven head, twenty-seven years on the force.

‘Not a bad day to be murdered either,’ Wickens replied. He was thirty-two, a lean and angular individual, a keen runner. ‘Could be an accident though. Messing about on the river.’

‘You’re a bit young to remember the song,’ Cottesloe said, turning to him.

‘What song?’