ITV’s Secret Service: cast, plot and everything we know about the new spy thriller

Prepare to be immerse in the world of spies, sleuths and undercover operations… because Secret Service is about to land on ITV and STV (Scotland), and trust us, this will be your next binge!

Gemma Arterton is heading back to our screens once again but this time, it’s authentic, it’s relatable and oh so very unmissable! 

Adapted from Tom Bradby’s 2019 novel of the same name, the series drops us into a world of intelligence, politics and secrets – the kind that don’t stay buried for long…

So if you’re on the hunt for your next edge-of-your-seat watch, you’ll want to tune into ITV1/ STV on Monday 27th April or stream all episodes on ITVX and STV Player! 

Let’s get into everything you need to know – from the plot to the Secret Service cast (and a few fun behind-the-scenes bits too).

What is Secret Service about?

Secret Service immerses us in the murky world of espionage, introducing us to Kate, who to the everyday person seems a loving, caring mum of two who works as a civil servant alongside her husband Stuart. But behind the illusion, Kate is the Head of the Russian Desk at MI6, regularly travelling for work and burying secrets that should never see the light of day!

When an op in Malta leads Kate to discover that a senior UK politician may be a secret Russian asset, it becomes a race against the clock – not just against her superiors, but against time itself – to uncover the politician’s identity, all while protecting herself and her family. But the deeper she goes, the harder it becomes to separate what’s real from what’s lies, because in this world, information is power… and some people will do anything to control it.

And what really stands out in this ITV drama is just how raw and real it feels. The everyday domestic life sits so naturally alongside the world of espionage, making everything feel unsettlingly close to home – and it really makes you wonder if your neighbour is quite who they say they are.

Who is in the cast of Secret Service?

Gemma Arterton as Kate Henderson

Arterton (St Trinian’s) plays Kate, the MI6 officer at the heart of the series. 

Rafe Spall as Stuart Henderson

Rafe Spall (Shaun of the Dead) stars opposite Arterton as her husband Stuart.

Avi Nash as Rev

Nash (The Walking Dead) plays Rev, a member of the Russian Desk team who reports into Kate.

Roger Allam as C

Like any other MI6 or British spy thriller there has to be a C, and in this case the role will be played by the one and only Roger Allam (Endeavour).

Alex Kingston as Rose

Kingston (Douglas is Cancelled, A Discovery of Witches) will play a supporting role as Rose, the Head of Security who's in charge of making sure Kate doesn’t put herself or the country in too much danger during her search for the truth.

Mark Stanley as Ryan Walker

Mark Stanley (Game of Thrones) plays the Labour Party’s Foreign Secretary who's at the centre of the unfolding conspiracy. 

Also expect to see Khalid Abdalla (The Crown), Alexander Terentyev, Amaka Okafor (The Responder, Bodies).

Fun facts about Secret Service

• Gemma Arterton has starred in several spy thrillers before, but says Secret Service is the most realistic yet, praising how grounded and authentic the world feels compared to typical spy dramas. 
• Gemma said working with Rafe Spall felt natural as they are “cut from the same cloth,” both sharing a South London background and a grounded acting style. 
• The production was filmed under a tight budget and challenging schedule, which the cast say added pressure but also helped keep performances sharp and focused. 
• Filming took place across locations including Malta and London, helping give the series a strong international spy-thriller feel. 
• The MI6 headquarters scenes were shot in a cold, damp building in Hayes, with the production building the office set inside it to keep everything feeling authentic. 
• Director James Marsh revealed the team even felt like they were “being a bit naughty” filming near real intelligence locations, adding to the atmosphere. 
• Having author and political journalist Tom Bradby on set was invaluable, as he could quickly confirm what felt realistic within the world of intelligence and politics. 
• Bradby originally wrote the story with a Conservative government in mind, but this was changed to a Labour government during development to make the political landscape feel more current and believable. 
• Gemma had access to a former intelligence official who worked on the Middle East desk, helping her understand how spies balance family life, emotional pressure and secrecy, not just field operations. 
• Gemma also connected personally to the role, saying that working extreme hours on set while raising young children helped her understand Kate’s constant juggling act. 

The trailer:

What’s the release date for Secret Service?

Secret Service will be available on ITV/ STV from Monday the 27th with all episodes ready to stream on ITVX and STV Player.

And if you're looking for even more recommendations, why not check out all the other shows coming out in 2026!