Meeting an abrupt corner, Rhona swung hard left to pull up behind a police car.

DS Jones came forward to greet her. ‘Dr MacLeod, you made it through the barrier?’

‘I did, thanks.’ Rhona looked up as the hum of a drone overhead caught her attention. ‘I see we’re being observed?’

‘It’s been around most of the day. We think it’s being launched from Castle Hill, but we haven’t located where yet. Still, if it spots our missing person, it’ll be doing us a favour.’

‘I take it there’s nothing back from the search party?’

He shook his head. ‘If she did walk into town she could have headed anywhere by bus or train. We’re checking out both possibilities and asking the public to help with possible sightings.’

‘So you have a recent photo of Karen?’

‘Fortunately, one was taken at the recovery cafe by Marge Balfour, when Professor Pirie visited the group. It’s not a great photo, but it’s the best we have.’

He walked Rhona to the front door. ‘Take as long as you like, Dr MacLeod. We’ve finished in there for now. I should say they’ve taken a few items for DNA purposes, which will come through to you. Here’s a list of what they took.’

Rhona viewed the cottage from the outside first. A traditionally stone-built single-storey house with a front porch, a window on either side and two skylights indicating a loft.

Stepping into the porch, she found a couple of potted plants on ledges, below which were two pairs of wellies, different sizes, and an umbrella. An inner door led into a hall with two doors leading off, plus a narrow passageway heading towards the back of the building.

The temperature in the hallway was comfortable, despite being near the front door, the warmth coming from her left.

The house had a familiar scent Rhona had noticed in other old buildings. It wasn’t unpleasant, more like lived in. Maybe it was the weathered stone or the wood finishes via the doors and floorboards.

She stood for a moment, deciding where to look first. On her left, the door lay half open. The one her right was firmly closed.

She chose to go right. As the clasp released and the door swung open, a rush of cold air caught her in its grasp. Now she understood why the team working on the cottage had kept this particular door shut.

Despite the time of day there was very little light, so she flicked on the switch. The room had the air of not having been disturbed for some considerable time. Even the visit from the SOCOs hadn’t changed that. The fireplace was empty apart from fallen soot, and Rhona’s nose caught a fleeting smell of damp, suggesting there hadn’t been a fire lit in that grate for some time. She stepped forward via the metal treads set out by the forensic team, intrigued by what looked like impressions on the soot.

Closer now, she made out the shape. Three lines meeting together to form a fourth, it looked undoubtedly like the footprint of a bird. Standing by the empty grate, Rhona was fairly certain she could hear the possible culprits cawing above her.