Line of Duty mastermind Jed Mercurio brings his new political series Trinity to Netflix. Richard Madden and Gugu Mbatha-Raw will lead the cast – but what is it about?

One of TV’s most successful writers returns to his happy place for a new thriller full of twists and turns.

Trinity transports viewers into a world of political intrigue, deep secrets, and shocking revelations. It’s also a story with a timely edge, as Mercurio weaves in elements of world-controlling conspiracies.

Leading the cast are Richard Madden and Gugu Mbatha-Raw. Richard previously worked with Mercurio on his 2018 hit political thriller Bodyguard. Meanwhile, Gugu has been keeping Tom Hiddleston’s God of Mischief Loki on his toes in the character’s namesake Disney+ series.

Keep reading for everything we know about Trinity, including its plot, cast, and start date on Netflix.

Read more: Secret Service ITV: Gemma Arterton and Rafe Spall lead new spy thriller

Gugu Mbatha-Raw as Jane in The Girl Before [Credit: BBC/42/HBO/Jason Bell]

What’s the plot of new Netflix series Trinity?

The stakes are high in the new Netflix drama Trinity.

Mercurio’s story looks at a bond between a high-power naval officer and an equally-influential politician.

As the pair’s relationship grows, it becomes clear that things aren’t quite as straightforward as they first appeared.

“A heroic female naval officer becomes involved with the outwardly charismatic secretary of defense, only to discover he may be at the heart of a dangerous conspiracy,” explains the official Netflix synopsis.

Gugu Mbatha-Raw and Richard Madden will star in TRINITY. A new high stakes drama thriller series from the creator of Bodyguard.

A heroic Naval Officer becomes involved with the charismatic Secretary of Defense, only to discover he may be at the heart of a dangerous conspiracy. pic.twitter.com/0Cm9dRxtUm

— Netflix (@netflix) June 24, 2025

Who will star in the cast?

Netflix has only revealed two names for Trinity so far, but they’re more than enough to pique our interest.

Mbatha-Raw will play Commander Katherine Decker. She’s second in command on the USS Kansas, which is “a nuclear submarine and one of the deadliest weapons on Earth”.

In addition to playing Ravonna Renslayer in Loki, Mbatha-Raw has also appeared in the much-loved San Junipero episode of Black Mirror, and episodes of Doctor Who. The actress will return to the Who-universe for this year’s spin-off series The War Between The Land of the Sea.

In 2021, she played the leading role of Jane in the tense BBC thriller The Girl Before.

Meanwhile, Madden plays Secretary of Defence Webb Preston. Described as highly charismatic (obvs), his technical expertise sets him apart from most other politicians. However, Netflix teases that his “innovation and purpose are seen as a threat in more ways than one”.

Madden might still be best known to many as Game of Thrones’ Robb Stark. However, he’s since appeared in several high profile movies including the 2019 Elton John biopic Rocketman, and Marvel’s 2021 feature Eternals. In 2023, he appeared in Prime Video’s action thriller Citadel alongside Priyanka Chopra, a role he’ll reprise in the upcoming sequel.

Trinity will reunite the actor with Mercurio after the pair worked together on BBC One thriller Bodyguard in 2018.

Richard Madden as Mason Kane in Citadel [Credit: Prime Video]

How many episodes is Trinity on Netflix?

Netflix has confirmed that there will be eight-episodes of Trinity. Although we don’t yet know how long each might last, we suspect each episode will be around an hour.

Mercurio has written the entire series and will also act as the showrunner.

Michael Cuesta will executive produce the show and direct episodes one and two. His previous work includes instalments of Homeland, Dexter and most recently, Daredevil: Born Again for Disney+.

When is it released?

Netflix has not yet released the start date for Trinity, but we’re hoping it will be soon.

More likely, though, we could have a long wait on our hands as the series has only just been announced and is not yet in production.

Perhaps we should have an eye on late 2026 or early 2027? Either way, the streamer is sure to dish out new details as production gets underway, so check back soon.

Trinity is coming soon to Netflix.