Oaks walked up the ramp of the suspect horse trailer. ‘Can you smell that? Disin-fucking-fectant. Jeez, Ronnie, the floor of this trailer has got less trace evidence on it than my bog seat.’ There were four other identical trailers in the main yard, all of which had been rented out to Mr Smart on numerous occasions over the previous three years. He always paid in cash and the keys were always left underneath a wheel arch, as he always collected and dropped off in the early hours.

As Goodwin approached, Oaks tried to hide his disappointment. He didn’t want Goodwin thinking he’d done anything wrong by cleaning the trailer so thoroughly, but Goodwin realised his mistake. ‘I’m sorry,’ Goodwin started, ‘if I’d known, I’d have left it as it was. But it’s booked out again this afternoon, so I . . . I cleaned it about an hour before you called.’ Then he quickly added that he’d of course cancel the afternoon booking and the trailer would remain where it was until Oaks was done with it. ‘It smelt of petrol,’ Goodwin said, desperate to make up for destroying all of their evidence. ‘And there were muddy tyre tracks inside.’

Oaks shared their suspicions that one of the gang rode a motorbike. ‘Yes, they could have been motorbike tracks,’ Goodwin agreed. ‘But there were also double tracks. Like a quadbike.’

Davidson stood in Goodwin’s yard, holding his mobile away from his ear. ‘A fookin’ quadbiiike!’ Gifford’s Midlands accent came to the surface as he ranted. ‘That means they had two recce vehicles, one of which can approach any property, over any nobbin’ terrain!’

Goodwin kept detailed records of everyone who hired his horse trailers, so he was able to provide a driving licence and phone number for Mr Smart. Oaks knew that both would be fake, but at least they would provide a starting point for two new lines of enquiry.

‘So, you left the keys under the wheel arch as requested and, in the morning, the horse trailer was gone?’ Oaks asked.

Goodwin confirmed that Mr Smart paid in full upfront, so he was more than happy to accommodate his requests. It wasn’t unusual for people to collect hire-vehicles during the night, because driving on empty roads was better for the horses and many of the local events and competitions started early. The trailer had been returned in much the same way: in the dead of night, with no witnesses.

‘I saw them.’ Oaks spun round to see a young lad with a broom in his hand. He was small, wearing tight clothes that showed off his lean body. Oaks guessed that he was in his late teens and definitely a jockey in the making. ‘I didn’t see them bring the trailer back, but I saw them pick it up.’