She and Hannah had gone to visit Jacob first thing that morning, swapping SD cards and batteries on all the cameras. Jacob seemed more vague about the whole business than he had been two days ago when they fitted the cameras, which made Dorothy worry. He said that he hadn’t noticed anything odd around the house, or going missing, in the last forty-eight hours, which didn’t add to Dorothy’s confidence that anything was even happening in Hermitage Drive at all.

Back at home, Hannah had showed her how to access the files on the cards, which filename related to which camera at which time. There was a lot of material to go through. This surveillance stuff was the bread and butter of the investigation business, Jim had told her more than once, but it was long, boring work. At least she didn’t have to sit in a car all day outside a home or office, waiting to catch sight of someone up to no good. But she still had to trawl through hours of this footage, even with motion-activated cameras.

She’d started checking the footage from the kitchen and study for the time periods Susan had been in the house, but there was nothing obviously suspicious. She then checked the living-room 161camera and the upstairs ones for the same time period. The downstairs cameras had a lot of footage for that time slot, but it was standard occupational-therapy stuff, exercises and so on, as well as boring things like Susan putting the kettle on, Jacob flicking through an old book. He had to go to the toilet often, and Dorothy would see him shuffling off screen with his walker, returning ten minutes later, sometimes with his fly still down. She was glad there wasn’t a camera in the downstairs bathroom.

For the same time period, the upstairs cameras had nothing, so it looked as if no one had been up there. Dorothy thought about what Jacob said, that an old television had gone missing from an upstairs bedroom. She should’ve checked to see if there was a dust shadow where the TV had been when she was at the house, but maybe the cleaner had been in since. That’s if it was even stolen in the first place. Dorothy wondered about the cleaner.

She paused the screen and closed her eyes. Tried to centre herself and opened them again. She picked up the two sheets of paper Hannah had printed off for her earlier, research on Susan Raymond. There was her LinkedIn profile, lots of praise and an apparently exemplary record as an occupational therapist since she graduated five years ago from Queen Margaret University and finished her training. A pretty normal Facebook profile and no presence on Twitter or Instagram, according to Hannah. But then, Dorothy was learning that people who seemed simple and innocent on the surface could have all sorts of hidden secrets.