‘The scabbing starts two inches below the centre of the ribcage. The injured area is five inches vertically and four inches horizontally. The scabs are in rough patches leading me to believe that the initial injury wasn’t a single incision. In that event, the most likely explanation is that these wounds were caused by an accident. I’m going to remove some of those scabs to preserve them and then cut around the wound so as not to damage any evidence that might be concealed immediately below the skin.’

Dr Lambert clipped the camera back onto its original mount on her computer, changed her gloves and picked up a scalpel.

Ava paused the footage once more, stood, stretched her arms and flexed her neck. She didn’t want to watch. It was her own fault. She knew she shouldn’t have come straight from the funeral to this. It was her job, though. She’d seen plenty of dead bodies before. Pointless being oversensitive now. She sat back down and pressed play.

The scalpel slipped easily into the taut skin just below the shoulder joint. Dr Lambert ran it diagonally downwards to the centre of the chest, returned to the other shoulder joint and made them meet.

‘Right,’ she said, ‘I’m deviating from my normal course.’ She pulled out the scalpel, prised up a few sections of scab, bagged them and set them aside for labelling and testing, then picked up her scalpel again. ‘The skin beneath those scabs was starting to heal, so I estimate those wounds were made some three or four days prior to death, confirming that this wound alone was not the immediate cause of death. There’s no infected tissue around the edge of the scabs or the wound. That was either very lucky, or the wound was properly cleaned at the time the butterfly stitches were applied.’

She dug the point of the scalpel into the base of the Y-section of incision in the chest and began drawing it downwards to open the abdomen and access the lower organs. Ava crossed her arms and took a deep breath.

The scalpel stopped. Dr Lambert frowned then stepped in closer, bringing her head down to the incision to see what the problem was. She tugged once, twice and the scalpel began moving again, then it popped out of the skin. She laid the tool down and slid her fingertips into the incision, one hand either side of the wound, teasing the skin apart, eyes as close to the abdomen as possible to identify the problem.

Ava heard the hissing before she saw anything happen.