“These tracks here, sir, the ones going down the forest track.” Lamb pointed at a muddy track that entered dense conifers. “They look like they might belong to the laird’s Land Rover. Thing is, sir, they only show a single vehicle. If he’d come back this way the tracks would cut across each other.”

Frankie crouched down to inspect the tracks more closely. “I think he’s right, sir. Do you think he drove down here and then had an accident?”

Corstorphine had a concern that this was exactly what had happened, although he wouldn’t be placing any bets on it being an accident. “Does anyone know where this track goes?”

They both shook their heads and Lamb pulled out his iPhone to try and load Google Earth, only to discover that 3G and 4G didn’t exist in the glen.

Frankie inspected the depth of the ruts left by the passage of a vehicle. “We’ll not get the car down here, sir. If we did manage any distance, we’d probably end up getting stuck.”

Corstorphine had to agree, the patrol car wasn’t up to off-roading. “OK. Lamb – you stay here, see if you can spot anything else that may assist us finding the laird. Frankie, we’ll go back to the station and pick up the Land Rover and some maps if we have them.”

Back at the station Frankie logged onto her screen and loaded Google Earth, zooming in on the laird’s house in an effort to see where the forest track went. She had to give up. The track split several times, making the network of paths that she could detect through the extensive tree plantations more like a maze. The map that Corstorphine had dug out from the office shelves didn’t deign to show anything as ephemeral as a forest track.

“We’ll just have to split up once we’re in the trees. Ask Hamish for the short-wave walkie-talkies, they should be good for around 10 miles, so we can at least keep in touch.” Corstorphine checked the back of the Land Rover for police tape and the first-aid kit. Both were present. Frankie jumped in the front with three walkie-talkies clutched in her hands.

Corstorphine checked the dash clock as he swung out into the high street. “OK. We’ve around 4 hours before the sun starts going down. If we haven’t found his Land Rover by then, we’ll have to call out the helicopter tomorrow morning, perform an aerial search.”

“We can’t call them out now, sir?” Frankie asked.

“No. We’re not even into an official missing person enquiry yet, and the ACC has to approve any helicopter use out of the regional budget. There’s no way he’d even look at it unless the sheriff has been missing for at least 24 hours.”