COLONEL ARKADY PETROV twisted around in his cramped seat and stared out of the frost-encrusted window of the Ilyushin Il-96 airliner as it lumbered eastwards across the skies over Siberia. Far, far below, in the sub-zero air, unobscured by any cloud, lay the vast white expanse of the endless Siberian taiga. Mile after mile of frozen forest: it had been nearly an hour since they had flown over anything even resembling human habitation. Colonel Petrov was not someone to spend a lot of time dwelling on the man they had pegged out in the cellar of that apartment block back in Moscow’s Cheryomushki district. What was his name? Konstantin Makarov? Yes, that was it. Well, they had what they needed from him and the man had already been temporarily reassigned – once they released him from the GRU’s own sanatorium – to a penal colony north of the Arctic Circle and just east of Archangelsk. Konstantin Makarov had eventually proved most forthcoming with information, once they had used the industrial bleach on him.

Information was power and Colonel Petrov had wasted no time. Using his GRU credentials, he had boarded the first official flight available from Moscow to the city of Novosibirsk, four time zones to the east, close to the Mongolian border and deep in the heart of Siberia. He was heading for the State Research Institute of Virology and Biotechnology, better known as VECTOR, a place infamous during the Cold War for its work on the Soviet bio-warfare programme, Biopreparat. Today it was one of only two places in the world – along with the CDC in Atlanta in the US – with declared stocks of the smallpox variola virus, and it was regularly inspected by the WHO as part of Russia’s accession to the Bioweapons Convention. All was not well at the VECTOR facility in the suburb of Koltsovo. That much Petrov knew. In late 2019 there had been a mysterious explosion on the fifth floor, in the decontamination room where scientists changed out of their protective suits. Windows were blown open, a fire had taken hold, and there were fears at the time of a possible global viral outbreak. Petrov, and many of his fellow officers in military intelligence, suspected then, and still did, that the explosion was a deliberate act of sabotage.