The story was that Tomo was looking for a gym to train at for mixed martial arts, which would put him in the sights of the Branko brothers. Using his real first name would mean he would react naturally when it was used. He hoped that impressing the brothers in the ring would be the key to the infiltration. Ivan had said that Luka Branko was ‘Good but not that good’ at MMA fighting, but was good at Brazilian ju-jitsu and grappling. He liked to be tested but was in possession of a massive ego and apparently didn’t react well if he lost. Tom was confident enough in his own ability to be able to take Luka close but still ‘lose’ by just enough to massage the Serbian’s ego, and hopefully make the right impression.

In these assignments, legends were kept as simple and as close to the undercover officer’s real history as possible. Simplicity made things easy to remember, especially when Ivan was introducing Tom to the Branko brothers. They wanted Ivan out of the picture pretty much straight away, as he wasn’t a professional, would be very jumpy and, to be frank, Tom didn’t trust him as far as he could throw him. Anyone willing to sell their friends and accomplices down the river for a few quid, or because of some pressure being applied, was at risk of switching sides back again if it was of some advantage to them. Informants were the lifeblood of covert policing, but Tom had never met one he could trust.

The cover story had been rehearsed and Liam, as cover officer, gave the official briefings, warning, as always, that Tom couldn’t act as an agent provocateur. This meant he couldn’t encourage others to commit a crime that they wouldn’t have committed without his involvement.

They were ready.

As soon as they entered the gym, the smells and noises instantly relaxed Tom; it was an environment he’d known since childhood. Ever since his papa had taken him to wrestle in the gyms in Sarajevo, he’d relished getting involved in contact sports.

He’d carried this on after settling in Scotland and then into the military, practicing the disciplines of grappling, boxing, kick-boxing, and Brazilian Ju-Jitsu, or BJJ. BJJ had become popular in the Marines while he was serving and was his sport of choice. He enjoyed that it was highly technical as well as brutally physical. Technique trumped size and power every time. The upside of BJJ was that you could practise all the time: something you couldn’t do in boxing, kick-boxing, or MMA unless you wanted to spend all your life nursing concussions. You could go full-bore at BJJ and grappling and, every time you were locked or choked out, you learnt a little more. A smaller guy could easily defeat a much bigger guy simply through technical expertise.