‘Sharon said the driver had a good look around the car park and then drove down the footpath, but only for a short distance, is that right?’ Tom asked.

Becky nodded. ‘I brought her out here to show me exactly where the car was parked, where they went. She finally admitted that she had arranged to meet someone here, but we haven’t managed to trace him. She didn’t know his name, and she’s adamant he didn’t turn up. We can’t rule him out, though, so we’re still looking.’

‘She should have come forward the minute she heard what happened,’ Tom said.

He felt a flash of irritation. Did she not appreciate that someone had died? But the fear of destroying her future husband’s trust in her before their wedding day must have been immense. Trust was such a huge issue in any relationship, and Tom couldn’t help thinking about Louisa. At what point could he risk telling her all that he had been keeping from her? Something he had read years ago sprang into his mind: Trust takes years to build, seconds to break, and forever to repair.

If Louisa found out he had been hiding the truth, she might never trust him again.

As he drove into the car park he could feel Becky’s eyes on him. ‘What’s up?’ she asked.

‘Nothing.’ He pulled the car to a stop. ‘Come on, let’s go for a walk.’

They followed the route Sharon said the car had taken along the footpath, then walked down the path to the hide. It was no longer a crime scene, and without the bustle of an active investigation it had a very different feel to it. The gloomy weather would keep all but the most enthusiastic of twitchers away from the place, and inside the hide it felt more dank and chilly than ever. There was no sound other than the rasping call of a mallard, and Tom gazed out of the viewing window at the water beyond. Brooding grey clouds reflected off the water, and the skeletal branches of leafless trees did nothing to cheer him.

He turned and looked towards the place where the dead woman had been sitting. There was no sign she had ever been there now, but the image was fixed in his mind. Had he missed anything? He closed his eyes for a moment, but nothing filtered through.

Why here?