A night out with his girlfriend goes badly wrong when Raza Shar is arrested and identified as a potential informant for London's Counter TerrorismSpecial Unit (CTSU). Detective Sergeant Gabe Waters is partnered with new recruit DC Holly Morten and introduces her to the world of informants. Ambitious and uninhibited, Holly pushes boundaries to get Raza on board. Gabe's key contact, Yousef, has information that links to a prolific terrorist, Ahmed El Adoua.
Gabe needs Raza to get closer to Dadir, the brother of Yousef, his missing informant. A nervous Raza struggles with his new role as he befriends and spends time with the unpredictable Dadir and his Bridge Town Crew.
The toll of Raza's double life begins to weigh heavily on him as he attends Yousef's funeral seeking information, but he finds a crucial new lead. Meanwhile, Gabe runs into a ghost from his past and his behaviour piques Holly's interest.
The CTSU team report to Headquarters on Raza's intelligence regarding Igli Gramos as their possible `Big Shot', and they mount a surveillance operation, with Raza at its heart, to follow the Gramos' money trail.
Holly's curiosity reveals the uncomfortable truth about Gabe's undercover past and her probing unwittingly leads to his two worlds colliding. Increasingly on edge, Raza reacts aggressively to Akash's growing influence on Nasir, whilst his family are caught up in the maelstrom of his double life. A new lead opens CTSU up to a line of investigation that puts Raza directly in the line of fire.
The terrorist cell is exposed and the final tragic details surrounding the attack on Café 66 are revealed. The fallout from these catastrophic events and revelations that follow change the lives of all those involved forever.
Paddy Considine
Gabe Waters
Bel Powley
Holly Morten
Nabhaan Rizwan
Raza Shar
Arsher Ali
Imran Aziz
Sharon D Clarke
Rose Asante