It was a quarter past four in the morning and the first glow of midsummer dawn was seeping above the horizon as Alan Wilson walked his black labrador on the verge along the A3050. He was heading for the Molesey Reservoirs Nature Reserve, hoping to get a good early walk for Lucky before the business trip to Scotland. He was in a good mood. The normally frantic road was almost deserted. The reserve would not be open yet, but Lucky had on a previous excursion found a good wide gap in the railings and seemed anxious to do some more exploring. What Wilson did not expect to see by the side of the road at that time of the morning was a young man wearing a bike helmet with a head-torch, bending over as if winded. Just a few yards away a bicycle was chained to a road sign. ‘Are you all right?’ he asked, from a safe distance, tightening the extendable dog lead. He hoped the man hadn’t been sick. Labradors have a habit of eating anything, however revolting.

‘He’s dead,’ the young man said, standing up, wiping a string of saliva from his mouth. He had a very odd movement in his eye.

‘Who?’

‘Through there,’ he said, pointing through the gap in the railings that Wilson had intended to use. ‘We need to call the police.’

Wilson peered through the fence. There was a dark shape ten yards away under the bushes. In the twilight it was hard to say what it was. Wilson considered going with the dog to investigate, but didn’t quite trust this scruffy individual, with his dirty shirt, head-torch and a cycle clip on only the right leg of his grubby trousers.

‘Who’s dead?’

‘The murderer, Neville Rollason.’

Wilson knew exactly who he meant but was sceptical of this young man’s claim.

‘Just killed him, then, have you?’ He asked the question in jocular fashion, but the answer was straight.

‘No, no, I found the body.’

‘Is that his bike or yours?’

The young man stood up to face him. ‘No, that’s mine.’

He wondered quite how a passing cyclist could have made this alarming discovery. The body, if that’s what it was, was not visible from the road. Lucky, sensitive as ever to the mood of her master, began to bark at the man.

‘Are you sure that’s actually a dead body?’ Wilson asked.

In answer, the young man proffered his phone, a photo luridly displayed.

‘Christ almighty!’ Wilson recoiled at the image. ‘Okay, I’ll call 999. But I don’t think you should go anywhere.’ As he put the phone to his ear he knew there was zero chance now that he would be on time for his train.