Incisor would still proceed to the café, but there could and should be no approach.

Julie had a lot of further questions – she had a forensic operational mind and a grasp of detail that was second to none – and they were on the call until she was satisfied she had all the answers.

Once they’d rung off, there were still the not inconsiderable issues surrounding their own team: how did they get safely in and out – and how did they communicate once they were there?

Kate said she was going in via Minsk, Julie that she would take Callum – who had sat spellbound through the entire briefing – the longer route via Riga. She had arranged a series of phones to be used in successive rotation. The first would be before the day of contact, the second on the day of the meeting only, the third between the rendezvous and the point at which Incisor might hand over whatever information he had gathered, and the final one for the journey out of Russia.

There was a great deal more and, by the end, even Kate’s concentration was beginning to flag. But there was one further curve ball to deal with. Towards the end of the discussion, Julie began to fret at their ability to pull off an operation with so few resources and so little back-up. In the middle of something of a tirade, Grove intervened: ‘I’ll come with you.’

They all looked at her in stunned silence. It was a while before Kate realized she was serious and the suggestion required a response. ‘You can’t,’ she said.

‘Why not? Julie was saying you have no one to run proper back-up, to take the role of point man, as she put it. Well, unless I’m mistaken, that doesn’t necessarily have to be someone from the intelligence community, does it? It could be a civil servant who is resourceful and experienced.’

‘No, I’m sorry,’ Kate said. ‘We don’t have the time to deal with all the reasons why this is not a good idea. I—’

‘I have an Irish passport in my maiden name, which I kept for superstitious reasons, but I don’t have to invent a very deep cover story. I can come in with you as a friend or lover on a weekend jaunt as a tourist to Minsk and Moscow. If something goes wrong, I can simply rock up at the embassy and throw myself on the mercy of the ambassador, perhaps with Callum, if necessary. He’ll have little choice but to help us and, while there might be something of a diplomatic rumpus, I don’t think we’ll spend the rest of our lives rotting in a Siberian gulag. We have the advantage of being genuinely clean skins, which, as I understand it, is what this operation lacks.’

‘We can’t carry anyone else,’ Julie said, as much to Kate as to Grove. ‘Callum can drive. He has a reasonable degree of deniability. He’ll say he’s my boyfriend and was duped. With enough diplomatic muscle, you could dig him out of a hole, but we can’t afford to have anyone else who—’