The voice was Jenny Li’s. She was back from Moscow, her temperature normal, but still recuperating in the Service’s country house in Sussex, where a medical team was monitoring her. She was clearly itching to be in on the action. Jenny had insisted on being patched through to the IOC at this late hour and Angela had taken the call immediately.

‘RIM?’ Angela replied. ‘You mean the Russian Imperial movement, that ultra-nationalist outfit based in St Petersburg?’

‘Similar, but it’s not them. It’s another group altogether. They’re in Moscow and they’ve got people inside state security. I had some interesting conversations while I was over there.’

Angela ran her fingers through her hair, swept it back off her forehead and sighed. Right now, more than ever, she craved a cigarette, but she had given up and that was that: she wasn’t going back. ‘I’m sorry, Jenny,’ she said, ‘but this makes no sense whatsoever. If that was the case then why would Colonel Petrov have given Luke this valid lead into the group over here?’

‘Listen to what I’m saying,’ Jenny replied abruptly. ‘It’s a turf war. Petrov is GRU. And these people are tied in to their rival agency, the FSB. Look, we’ve known for some time there’s been an inter-agency rivalry between those two. The GRU’s been making a lot of waves recently on the international scene – Salisbury, Montenegro, Ukraine, the downing of Malaysian airliner MH17 – and that’s obviously pissing off people in the FSB.’

‘And so? What’s your conclusion?’ Angela could be abrupt herself at times, but the two women had worked together long enough that neither took offence.

‘Let me give you what I think,’ Jenny Li said. She went quiet for a moment and Angela thought the line had dropped out.

‘Sorry,’ Jenny resumed, ‘just had to wait for someone to go past.’ She sounded none the worse for her recent ordeal in Moscow – in fact, the Service’s foremost expert on CBRN seemed more alert than ever. ‘So, it may well be that Agent X was originally intended for a specific target on Moscow’s hit list – Chechen separatists, jihadists in Idlib, who knows? It’s hard to see a biological weapon this sophisticated getting developed without the use of a state laboratory. But—’

‘I thought there was a “but” coming,’ interjected Angela.

‘But it’s ended up in the hands of this far-right transnational group and it looks very much like someone in the FSB is trying to exploit Russia’s inter-service rivalry.’

‘How exactly?’

‘Isn’t it obvious? By helping an ultra-nationalist group acquire the pathogen, then dumping all the blame on to the GRU. They actually want Petrov and his people to take the rap for this. They want to bring him down, to clip the GRU’s wings, as it were.’