Kate flicked her head at Spencer and he walked back to his police car, shamefaced. Kate felt sorry for him in a sense; she knew what he meant: at least the body had turned up, even if it was in this grisly fashion. Poor Mr and Mrs Butler.

‘The pathologist thinks he attacked her again last night. Whether or not it was sexual he doesn’t yet know. He thinks the face was beaten recently, but he could find no evidence of a sexual assault.’

‘Probably wanked over her. That wouldn’t leave anything.’

‘I’m not so sure. Look at the way her hair has been arranged, the way the dirt’s been smoothed around her. I think he was searching her. We know he’s a nutter, and we know he’s a sexual deviant.’

Kate knelt by the girl’s body, repressing a shudder at the rancid smell. ‘Suppose he thought he’d left some evidence on the body? What, I don’t know. He could have come back, dug her up, searched her. Then when he didn’t find what he wanted, or maybe even when he did, he attacked her. It’s got a kind of twisted logic to it.’

Caitlin nodded. ‘Sure you always was a clever girl, Katie. I think you’re probably right. But this man has finally made his biggest mistake . . . He’s wound me up, Kate. He’s pushed me too far this time. When we find him - and we will - I’m going to beat his fucking brains in!’

Caitlin looked towards the uniforms and shouted: ‘Where’s the bloody undertakers? Get this child covered up and into a body bag.’

Kate stood up. In the grey light of day Caitlin looked terrible. His haggard face with its grey stubble seemed to have sagged overnight. For all his faults, and they were legion, at that moment Kate almost loved him.

‘Come on, come back to the station with me and let forensic finish their work here.’

She took his arm and pulled him away gently. ‘We’ll go and get some hot coffee inside us.’

Both noticed she didn’t mention breakfast.

Ronald Butler walked into the mortuary at Grantley Hospital, Kate beside him. The mortuary assistant pulled the white sheet from Louise’s body and Ronald Butler stared down at the remains of his daughter. Kate looked away. Out of the corner of the eye she saw the man’s hand go up to his mouth.

‘Is this your daughter, sir?’ Her voice was low. The formal identification had to be made.

He nodded and then bent double. The mortuary assistant quickly covered Louise up and both he and Kate rushed to Butler. He was now holding his chest tightly, and as he collapsed on to the floor Kate shouted: ‘Get the bloody Crash team now. He’s having a heart attack!’

When the assistant had run off she loosened the man’s shirt and tie.