Tucking her fingers into the loop, Ava pulled upwards. The floorboards had been nailed together and a trapdoor cut, carpet and all. Beneath it was darkness. Ava took the steep steps, one after the other, which seemed, ridiculously, to be leading to the outer wall of the house.

‘What is it?’ Tripp shouted from the hallway.

‘Trapdoor. Come into the wardrobe,’ Ava shouted. ‘A sort of hidey-hole; although this type of property wouldn’t have needed one, historically speaking, and this was made recently enough to stick modern carpet to it. It doesn’t seem to lead anywhere …’

‘Ma’am!’ Tripp shouted as her last word turned into a scream he heard half from within the bedroom and half though the open window.

Jumping down into the hole, he found her hanging out of a miniature door that opened into the cold clear air. Tripp pulled her back and she landed roughly on top of him, at the base of the steps.

‘You all right?’ he asked, panting.

‘I’d be better if I could stop nearly falling off high walls,’ she puffed. ‘What in God’s name is this?’

‘Stay there and hold on,’ Tripp said. ‘Wait until you hear my voice to open that door again.’

By the time Ava had recovered her breath, Tripp was shouting for her to open the door. She did so tentatively, pushing it with her feet and keeping well away from the edge.

‘There’s a lot of latticework with ivy all over it,’ he shouted up. ‘But I think there’s a proper structure beneath, more like a ladder.’

‘So the farmer was expecting company at some point,’ Ava said. ‘Which explains why our killer went upstairs after finishing his business with Mr Moffat. If he heard footsteps, he’d have had to make sure there was no one else in the house. By the time he got up here, our potential witness was already in this hole and ready to climb the ladder.’

‘And they’d been trained to climb it. We walked right next to it to get in the back door and didn’t notice it. No one could have found this by chance.’

‘There was a packet of condoms in the bedroom,’ Ava said. ‘Our victim might have been unmarried, but I don’t think he was entirely single.’

‘Makes sense,’ Tripp confirmed. ‘I just got off the phone with the local pub landlady. She got a call early this morning from the farmer’s mobile, knew the number as the caller ID came up on her phone. It was a woman’s voice telling her Mr Moffat was dead and here’s the interesting thing … The accent was definitely not Scottish or English. When pushed, the best she could say was that it sounded like an African accent; although the caller said few words then rang off.’

‘We’ve got a witness,’ Ava said. ‘About bloody time.’