‘I managed to get through to one of the detectives who interviewed him after he crashed the party,’ she continues, glancing at her notes. ‘An officer called Manu Jabthian. He’s teaching these days, at somewhere called the Bang Kaen Detective Training School.’

Nice work if you can get it. Maybe Silas should offer his services. He fancies a trip to Thailand.

‘How long have you been in?’ he asks, knowing that this sort of spadework takes time.

‘I couldn’t sleep,’ Strover says.

‘You’ll make yourself ill,’ Silas says, particularly if she eats a single apple every morning and insists on calling it breakfast. Kate was pushed too hard. He’s wary of Strover going the same way.

‘Manu says he remembers the case well,’ Strover continues, checking her notes again.

‘What exactly was Gilmour arrested for?’

‘Causing trouble at a private party on Ko Samui – Chaweng beach, in the northeast of the island.’

‘Is that all?’ he asks.

‘Off his head on drugs, apparently. But get this – someone saw Gilmour on the beach waving around a handgun. That’s why the police were called.’

Silas looks up.

‘Do we know what sort of gun?’

‘According to Manu, Gilmour was unarmed by the time the police arrested him. They let him go in the end – nobody at the party was willing to give statements. He had no ID or passport on him and wasn’t making a lot of sense, but they assumed he was British.’

‘What happened to him afterwards?’ Silas asks, looking at the police mugshot again, his mind racing.

‘That’s why Manu remembers the case,’ she says. ‘Two days later, a body washes up on the same beach, gunshot wound to the head. The police try to call in Gilmour for questioning again, but they can’t find him. He’s vanished.’

‘And the bullet?’

He already knows the answer.

‘Same markings as the one fired in Cornwall.’

His boss is going to love this.

‘Who was the victim?’ Silas asks.

‘Small-time drug dealer from Bangkok. Police weren’t too concerned.’

He knows the feeling. But the Royal Thai Police would have filed a report linking the Ko Samui case to Gilmour Martin, suspected of being a UK citizen. No real evidence, but enough for the National Ballistics Intelligence Service to flag up a possible British connection.

‘Do we have any idea where Gilmour is now?’ Silas asks.

‘The Home Office doesn’t have a record of anyone of that name matching his age,’ she says, turning to her laptop. ‘I’ve looked everywhere else too. Mispers, Europol, Interpol.’

He knows Strover would have been thorough, doesn’t want to think how long she’s already been working on this.

What about the DVLA?’ he asks. ‘Anything on the “care of” address in London?’