London, 1886 and Mr Adolf Verloc runs a sex shop in the heart of Soho. Unbeknown to his loyal wife Winnie, Verloc also works for the Russian embassy, spying on a group of London anarchists.

The Russian government 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 anarchist, The Professor, to supply explosives for his mission - an act which attracts the attention of Chief Inspector Heat of Scotland Yard. Caught between the spy masters and the police, Verloc grooms Winnie's young and vulnerable brother Stevie as his unsuspecting accomplice. When the truth and consequences emerge, Verloc must face Winnie's wrath ...

From the producers of the acclaimed Line of Duty, this riveting psychological thriller stars Toby Jones as Verloc and Line of Duty's Vicky McClure as Winnie, with Stephen Graham (Boardwalk Empire) and Ian Hart (The Last Kingdom). Adapted by BAFTA award-winning Tony Marchant (Great Expectations) and directed by Emmy award-winning Charles McDougall (Hillsborough, House of Cards, The Good Wife), The Secret Agent will be broadcast on BBC One this summer.