They walked slowly through the whole house, Marie stopping to pet the gorgeous long-haired tabby cat that had sidled up to her, purring contentedly.

They finished up in the lounge, where they stopped and stared at the vast array of photos, hunting for a telltale space. ‘Ah, got it,’ Marie said. ‘Look, Gary.’ She pointed to two small, framed photographs on top of a bookshelf. Between them was a slim, clean line in the dust. They asked Mrs Miles if she remembered what had stood there.

‘It was a picture of my nephew, Davy, and it was in a silver frame. Where’s it gone?’ Natalie looked utterly confused.

‘Mrs Miles,’ said Marie softly, ‘you are the fifth person this week to have had a photograph stolen. We still don’t know why this man is doing it.’

‘But you can rest assured that he isn’t here, Mrs Miles. I just have to check the garage, then we’ll be done. He’s a long way from here by now, I promise you.’ Gary went back into the kitchen and opened the door to the integral garage. The place clearly wasn’t used for a car, housing instead a chest freezer, garden tools, a mower, several stepladders and a pile of boxes all marked ‘Xmas Decs’.

The main garage door was locked fast, and there was no personnel door. You accessed it either from the main door or the kitchen. It was chock full of stuff, but there was nowhere to hide a man. Gary went back into the kitchen.

‘Is the door from the kitchen normally locked, Mrs Miles?’ he asked.

‘No, the garage is a handy dumping ground — as you probably noticed,’ she said. ‘I’m always in and out to the freezer. No one could get through the outer door without a key and it sticks dreadfully, you’d hear anyone who tried.’

They sat around the kitchen table. Marie asked Natalie if she would talk them through her evening. ‘And Gary will make you a cup of tea.’

Gary smiled. ‘Of course.’

Natalie stood up. ‘No, I’ll do it. You’ve been very kind, and I feel much better now. It’s good to know I’m not the only one this man’s targeted. I don’t feel quite so much a victim.’ She made them all tea, then described her evening.

At first, Marie couldn’t help wondering if Natalie’s nervousness had been down to the book she was reading or just her enforced idleness. By the time Natalie had finished recounting her movements, she was certain their killer had slipped inside before she closed the windows, hiding somewhere until she had gone to sleep. She kept this to herself.

‘Tell us about that picture of Davy, your nephew,’ Gary said.