ITV’s ‘Secret Service’ spy thriller ends with husband unmasked as Russian mole

Key facts

• Gemma Arterton stars as MI6 officer Kate Henderson, head of the Russia Desk.
• Rafe Spall plays Stuart Henderson, Kate’s husband, revealed as the Russian mole in the finale.
• The series is adapted from Tom Bradby’s 2019 novel and co-written by Bradby and Jemma Kennedy.
• Oscar-winning director James Marsh directed the first three episodes; Farren Blackburn directed episodes four and five.
• The five-part series was filmed on location in Malta and London.
• Ryan Walker (Mark Stanley) wins the leadership election to become Prime Minister after rival Imogen Conrad’s sex tape leak.
• The mole’s recruitment is traced to a simultaneous visit by Kate and Stuart to Prague, where Stuart met Russian operative Igor Borodin.
• The series is produced by Potboiler Productions and commissioned by ITV’s Director of Drama Polly Hill.

A familiar face behind the betrayal

ITV’s espionage drama Secret Service reaches its climax with a twist that upends the entire investigation: the Russian asset embedded in the British government is not a politician or a civil servant, but the husband of the MI6 officer leading the hunt. Kate Henderson, played by Gemma Arterton, discovers that her husband Stuart (Rafe Spall) has been passing intelligence to Moscow for years. The revelation comes after Kate pieces together that both she and Stuart were in Prague at the same time as Russian operative Igor Borodin — the moment Stuart is believed to have been recruited. What began as small pieces of political information escalated into a full-blown espionage operation, with Stuart unable to extricate himself from the web of deceit. By the time Kate assembles the evidence, the damage is irreversible. The finale leaves the couple’s relationship shattered and Kate’s professional future in jeopardy.

A leadership race tainted by scandal

The political backdrop of Secret Service is a fraught Conservative Party leadership contest triggered by the Prime Minister’s resignation. The two main candidates are Home Secretary Imogen Conrad (Amaka Okafor) and Foreign Secretary Ryan Walker (Mark Stanley), a man described as an “oleaginous sod in tasselled loafers” with questionable ties to the Russian foreign minister. Walker ultimately wins the race after a sex tape involving Conrad is leaked, derailing her campaign at a critical moment. The series does not explicitly state who leaked the footage, but the timing benefits Walker, whose off-piste activities — including a friendship with the Russian foreign minister and flirtations with nationalism — raise suspicions among intelligence chiefs. With Walker installed as Prime Minister, Kate’s investigation into Russian interference at the heart of government becomes even more urgent — and more dangerous.

A serious drama with a serious message

Secret Service, adapted from Tom Bradby’s 2019 novel by Bradby and screenwriter Jemma Kennedy, is a self-consciously weighty thriller. Unlike the sardonic tone of Slow Horses, this series takes itself with utmost seriousness. Even moments of potential levity — a flirtatious Russian double agent, a sex tape involving a prominent politician — are presented with the solemnity of a classified briefing. The show’s creators have leaned into the contemporary geopolitical landscape, exploring long-standing tensions between Russia and the UK and posing urgent questions about the extent of Russian interference in British politics. “Democracy is stuffed,” the series seems to hiss from a darkened doorway, as characters deliver desk-thumping statements like “The last thing we need is allegations of Russian collusion. We all know what happened in America.” This earnestness may alienate viewers seeking the irreverent banter of rival spy dramas, but it also gives the series a distinct identity: a thriller with the brass neck to address hot-potato global skulduggery while focusing on its implications for Britain’s national security.

Award-winning talent behind and in front of the camera

The series marks a creative reunion between Tom Bradby and Oscar-winning director James Marsh, who previously collaborated on the feature film Shadow Dancer. Marsh, best known for Man on Wire (which won the 2008 Academy Award for Best Documentary Feature) and The Theory of Everything, directs the first three episodes. Farren Blackburn, whose credits include Gangs of London and A Discovery of Witches, directs episodes four and five. The ensemble cast is led by Gemma Arterton, whose recent credits include Funny Woman and The Critic, and Rafe Spall, known for Under the Salt Marsh and Jurassic World: Fallen Kingdom. Supporting players include Mark Stanley (Adolescence, Happy Valley), Amaka Okafor (Bodies, The Responder), Rochenda Sandall (Amandaland, Small Axe), Alex Kingston (Douglas Is Cancelled, Doctor Who), Roger Allam (Endeavour, The Choir), and Avi Nash (Silo, The Walking Dead). Roger Allam, who plays MI6 boss Sir Alan Brabazon, delivers a performance that one critic noted “bears out my theory that there is no programme on Earth that wouldn’t benefit from his presence.”

Production and distribution details

Secret Service is produced by leading independent producer Potboiler Productions, with Gail Egan (Funny Woman, A Most Wanted Man) and Andrea Calderwood (The Buccaneers, The Boy Who Harnessed the Wind) serving as executive producers. The series was commissioned for ITV by Director of Drama Polly Hill and overseen by Drama Commissioner Huw Kennair Jones. Filming took place on location in Malta and London, with Malta standing in for the base of Russian oligarch Igor Borodin. All3Media International are co-commissioners and will handle international distribution of the drama. The five-part series is described by ITV as “suspenseful, timely and cinematic,” promising a powerful drama that captures the complexity of contemporary geopolitics while delivering edge-of-your-seat storytelling.

A familiar formula, confidently executed

While Secret Service does not break new ground in the espionage genre, it compensates with confident pacing and slick direction. The plot — a senior MI6 officer juggling family life and a secret career, a hunt for a Russian mole in the government, a leadership contest, and a murder that thrusts the team into the spotlight — hits familiar beats. But the series executes them with enough verve to keep viewers engaged. Critics have noted the show’s reliance on genre clichés: actors in wool-blend car coats striding purposefully past the SIS building, shouting lines like “You’re the bloody home secretary!” and “Tell that to the prime minister!” Yet the series is “nothing if not tenacious,” as one review put it, and there are enough big events — murder, guns, political scandal — occurring at regular intervals to maintain momentum. For those who find the stiff-jawed approach to Cold War unpleasantness off-putting, there is always next week’s glossy espionage drama. But for viewers seeking a serious, well-acted thriller that takes its subject matter seriously, Secret Service delivers.

The bottom line

• The Russian mole in ITV’s Secret Service is Stuart Henderson, husband of MI6 officer Kate Henderson, recruited during a joint trip to Prague.
• Ryan Walker becomes Prime Minister after a sex tape scandal derails rival Imogen Conrad’s campaign.
• The series is adapted from Tom Bradby’s 2019 novel and co-written by Bradby and Jemma Kennedy, with Oscar-winning director James Marsh helming the first three episodes.
• Filmed in Malta and London, the five-part series is produced by Potboiler Productions and distributed internationally by All3Media International.
• Secret Service adopts a serious tone, avoiding the banter of shows like Slow Horses, and focuses on Russian interference in British politics.
• The show features an ensemble cast including Gemma Arterton, Rafe Spall, Roger Allam, and Alex Kingston.