The Restless Dead - Simon Beckett

'Composed of over sixty per cent water itself, a human body isn't naturally buoyant. It will float only for as long as there is air in its lungs, before gradually sinking to the bottom as the air seeps out. If the water is very cold or deep, it will remain there, undergoing a slow, dark dissolution that can take years. But if the water is warm enough for bacteria to feed and multiply, then it will continue to decompose. Gases will build up in the intestines, increasing the body's buoyancy until it floats again.
And the dead will literally rise . . . '

Once one of the country's most respected forensics experts, Dr David Hunter is facing an uncertain professional - and personal - future. So when he gets a call from Essex police, he's eager for the chance to assist them.

A badly decomposed body has been found in a desolate area of tidal mudflats and saltmarsh called the Backwaters. Under pressure to close the case, the police want Hunter to help with the recovery and identification.

It's thought the remains are those of Leo Villiers, the son of a prominent businessman who vanished weeks ago. To complicate matters, it was rumoured that Villiers was having an affair with a local woman. And she too is missing.

But Hunter has his doubts about the identity. He knows the condition of the unrecognizable body could hide a multitude of sins. Then more remains are discovered - and these remote wetlands begin to give up their secrets . . .

With its eerie, claustrophobic sense of place, viscerally authentic detail and explosive heart-in-mouth moments, The Restless Dead offers a masterclass in crime fiction and marks the stunning return of one of the genre's best.