London, 1886: Verloc (Toby Jones) runs a sex shop in Soho. Unbeknownst to his wife Winnie (Vicky McClure), Verloc also works for the Russian embassy, spying on a group of London anarchists. The Russians are furious with the English establishment’s indifference to the anarchist threat gripping the rest of Europe. So Verloc is assigned a mission: blow up the Greenwich Observatory and make it look like a terrorist attack to provoke a crackdown. Should he fail, Verloc’s real identity as a spy will be exposed to his vicious comrades. Verloc is forced to turn to the volatile Professor (Ian Hart) to supply explosives which attracts the attention of Chief Inspector Heat of Scotland Yard (Stephen Graham). Caught between the Russians and the police, Verloc makes Winnie’s brother his accomplice..