‘Yes – at least that’s what we call it. Officially it’s Room 13.2 or something suitably anodyne, but nobody calls it that. Think of it as our own in-house theatre production studio, if you will. It’s where we set up certain … scenarios for critical missions. Like this one.’

She took out a cardkey from a pocket in her boiler suit, held it against the reader and keyed in a code. ‘I should warn you, Luke,’ she said, as the lock released with a soft click, ‘that most of the Service doesn’t even know this place exists so you won’t be able to talk about it upstairs. Is that clear?’

‘Crystal.’

The room they walked into looked nothing like an office space. Instead, Luke found himself inside what seemed to be some sort of garage, and a filthy, unkempt one at that. Blackened, oily car parts lay against the wall and on shelves that seemed in serious danger of collapsing. A peeling poster of a Mazda MX5 car was pinned to the wall above a moth-eaten beige armchair, and the whole place was lit by a flickering neon striplight on the ceiling. An old fridge stood in the corner with a crate of Corona beer balanced on top. The only other furniture was a worn-out workbench and a chair on casters. Three people, whom he had never seen before, stood in front of it. The woman in the middle of the group nodded to acknowledge Angela, then stepped forward to greet Luke.

‘Welcome to the Stage,’ she said. ‘I’m Dextra and I’ll be supervising your transformation.’ She looked to be in her early thirties, with designer glasses, jeans, T-shirt, clipboard and, he couldn’t help noticing, immaculate white teeth. She took off her glasses and took a pace closer to him. ‘From now on,’ she said softly, as if this were a secret to be shared with no one else in the room, ‘you’re no longer Luke Carlton. You’re Steve Keane. I want you to become him, to think like him, scratch, fart, pick your nose like him. In short, I want you to crawl inside his character and be him. Think you can do that?’

No one had spoken to Luke quite like that since basic training, but he didn’t mind one bit. ‘Got it,’ he replied. He could feel his pulse quickening. This was going to be intense, he could tell, and that suited him just fine.

‘So,’ she said, rubbing her hands together in anticipation, ‘you’re ours for the next three days while we prep you for this mission. Technically, as this is UK soil you’re going to be operating on, it now becomes an MI5 lead. But this place …’ she swept her arm around the mocked-up garage they stood in ‘… the Stage, is unique to the Service. There’s nothing like it in either Thames House or Cheltenham.’