Betrayal | Preview (ITV1)

Shaun Evans (Until I Kill You, Endeavour, Vigil), Romola Garai (The Years, The Hour), and Zahra Ahmadi star in a gripping thriller about trust, truth, and the personal cost of secrecy in the modern intelligence world.

Written by award-winning playwright and screenwriter David Eldridge and directed by BAFTA and Emmy nominee Julian Jarrold, the series is set against the backdrop of MI5 and explores the fragile, tangled web of human relationships, where loyalty and deception collide.

At the heart of the story is John Hughes (Evans), a mid-career MI5 officer navigating a rapidly evolving intelligence landscape while struggling to keep his personal life intact. Acting on a hunch, John meets a British-Iranian man with links to the Stockport gangland who claims to have intelligence about an imminent plot on UK soil.

When the encounter takes an unexpected turn, John finds himself under internal investigation, facing scrutiny from his superiors including Simone Grant (Nikki Amuka-Bird), while his partner Claire (Garai) grapples with the secrecy that defines his world. John’s efforts to save his marriage are complicated by his inability to let the case go - when he meets Mehreen Askari-Evans (Zahra Ahmadi), an intelligence operative who is tasked with taking over John’s duties, he finds an unlikely ally.

As John becomes increasingly convinced of the involvement of a hardline faction of the Iranian regime, he also starts to worry there are enemies closer to home. Can he identify the target and avert the attack before it’s too late?

Betrayal stars Gamba Cole (The Outlaws, Three Little Birds), Omid Djalili (The Letter for the King, His Dark Materials), Matthew Tennyson (A Midsummer Night’s Dream, Grantchester), Hayley Tamaddon (Unforgotten, Coronation Street), Anthony Flanagan (Protection, House of the Dragon).

Plus Paddy Rowan (G’wed, Four Lives), Waj Ali (Out There, Dead & Buried), Karim Kadjar (Wolf Hall), Emma Cunniffe (Suspect: The Shooting of Jean Charles de Menezes, The Long Shadow), Georgina Rylance (Benediction, Sherlock), Ben Lambert (Outlander, The Crown).

And Julia Watson (Doctor Who, Doctors) and Julian Wadham (Black Doves, The Crown), alongside newcomers Elham Karimpour, Aidan Rivers, Corin Silva, and Eliza Agrosoaie.

Betrayal begins Sunday 8th February at 9pm on ITV1.