Interpol had been looking for a disgraced finance executive for weeks when Christo Grozev, an investigative journalist, found him, hiding in Belarus. Grozev had become expert at following all-but-invisible digital trails – black-market mobile phone data, passenger manifests, immigration records – to unmask Russian spies. These were the sleeper cells living in Western countries and passing as natives, or the people dispatched to hunt down dissidents around the world.

He identified the secret police agents behind one of the most high-profile assassination plots of all: the 2020 poisoning of Russian opposition leader Alexei Navalny. That revelation put Grozev in Russian President Vladimir Putin’s crosshairs. He wanted Grozev killed, and to make it happen the Kremlin turned to none other than the fugitive financier, who, it turns out, had been recruited by Russian intelligence. Now the man that Grozev had been tracking began tracking him. The fugitive enlisted a team to begin the surveillance.