‘I only had a chance to speak to Sir Alan briefly on the way down here.’ Kate noted they had not offered to share a car with her and that Suzy appeared keen to underline the fact. ‘The read-out from the room is worse than the headlines. We’re looking at a total split in NATO. Germany, France, the Benelux countries, everyone on Europe’s eastern flank – in fact, pretty much everyone else – is keen to send reinforcements to Estonia, even if the crisis is receding. Washington and London insist that would be provocative.’

Kate wondered if this fissure in NATO had been the true purpose of the entire episode. If the Russian president’s primary foreign-policy aim was to fatally divide his enemies, he was doing an exceptional job. He’d regained control in Syria, was busy attempting to hold the whip hand in Libya. Who knew where his ambitions really ended? ‘What does the foreign secretary have to say about it?’ she asked.

‘I don’t know, but I guess we’re about to find out.’

The butler – if that was what he was – put his head around the door. ‘Mrs Henderson?’

Suzy got up with Kate. The butler raised a hand and an eyebrow at her. ‘Just Mrs Henderson, please.’ He led Kate along the hallway to one of the drawing rooms, where the windows were open to the expansive gardens and a lake in the distance, illuminated now by a bright moon. Despite the chill breeze, there was a hint of spring in the smell of newly mown grass.

Meg Simpson and Sir Alan sat opposite each other in stiff-backed chairs. There were gloomy old masters on the walls, an ornate white fireplace in front of them and a rich Afghani rug on the floor. As an image, Kate thought, it was every conspiracy theorist’s fantasy of how a British foreign secretary and the head of SIS might conduct their business.

The foreign secretary, in particular, looked tired, as if the last few days had aged her considerably. ‘I’ve reviewed the files,’ she said, without introduction or small-talk. ‘And it’s my view that we should proceed to the next stage of this operation. You have the offer to meet Mr Borodin’s son in Berlin?’

‘That’s right, ma’am. I’ve suggested Tuesday at ten a.m.’

‘What would it involve?’

‘In terms of resources?’

‘If you could just give me an outline . . . I’m not familiar with how such operations work.’

Kate glanced at Sir Alan as she tried to assess what was really being requested here. No minister she’d dealt with before had wanted to know the nuts and bolts of such a relatively simple operation. ‘I would go with one or both of my deputies as back-up. Then we’d have a team on the ground to conduct the requisite covert surveillance, just to ensure that neither side was being watched or followed and that the meeting would be able to take place in relative security and secrecy.’