There was a printer on the desk so I switched it on and selected a page to print off. It was an online news feature about the murder six months ago of a town mayor in the state of Sinaloa, on the west coast of Mexico. The headline read: New Mayor Shot Dead, and it told how the young, idealistic politician, Gisela Serrano, was gunned down outside her home just three weeks after she pledged to root out dishonest government staff and expunge corrupt contracts in lucrative public services. Two bullets were fired into her body by an assassin who rode by on a motorbike.

Police suspected the killing was carried out by La Asesina on the orders of the Sinaloa cartel who feared the mayor’s policies would impact on their businesses.

Once the page was printed I rushed back into the kitchen with it. I removed the tea towel from around Carver’s head and held the sheet of paper in front of his face.

‘Is this the woman who’s working for Slack?’ I said. ‘The co-called Slayer.’

His voice came out in a wheeze. ‘I don’t know what you’re talking about.’

‘Is that right? Then tell me why you’ve been searching online for information about her. I checked the Google history on your computer. The one you keep hidden in that secret little office that my colleagues obviously failed to discover.’

He shut his eyes and exhaled, as if blowing out candles on a birthday cake.

‘You’ve been rumbled, Carver,’ I said. ‘This woman they call The Slayer rides a motorbike. So does the bitch who shot my partner. She also works for the Sinaloa cartel, which we know has a business arrangement with the firm. You lot distribute drugs for them in the UK.’

He opened his eyes, shook his head, said, ‘You had no fucking right to go on my computer. You don’t have a warrant. Whatever I’ve been doing online is my business.’

I felt a surge of anger, but repressed it.

Instead, I said, ‘I’m about to call this in. So in a little while this house will be swarming with officers, including techies who will seek out whatever you’ve got hidden on that computer and on those phones that you didn’t tell us about.’

I’d found three smartphones in the desk drawer. They were all locked, and passwords were needed to open them. But I couldn’t help thinking, and hoping, that at least one of them had been used to send the threatening text messages.

‘You won’t get away with this,’ Carver screamed at me.

‘I already have,’ I said. ‘So there’s no point holding back. Just tell me if Slack did a deal with the cartel to use this woman. And where is she?’