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Six Four — cast, plot and all about the new crime thriller

Kevin McKidd leads the cast in Six Four.
Kevin McKidd leads the cast in Six Four. (Image credit: Getty)

Six Four on ITVx and ITV sees a police detective trying to find his missing teenage daughter in this drama based on Japanese bestselling thriller by Hideyo Yokoyama (opens in new tab). 

Played by Grey’s Anatomy star Kevin McKidd, Chris O’Neill is a serving police officer whose own daughter’s disappearance leads him to the unresolved case of a missing local girl called Julie Mackie. As Chris delves deeper into Julie’s case he uncovers evidence of errors, corruption and unbridled ambition. Meanwhile, his wife Michelle, a former undercover officer played by Vinette Robinson, decides to look for their daughter alone, leading her deep into the criminal underworld.

“I never take for granted the privilege of being an actor and the chance to become characters like Chris O'Neill, a hard-working serving police officer, whose teenage daughter has gone missing in Six Four,” says Kevin McKidd. “I'm delighted to be returning to my native Scotland and to be partnering Vinette Robinson as my on-screen wife, Michelle.” 

Here here’s everything you need to know about the compelling crime thriller Six Four

Six Four release date

Six Four is four-part series that will premiere on ITV’s new streaming service ITVX in 2023, before transferring to linear transmission on ITV shortly afterwards. 

Six Four plot 

In Six Four, Chris O’Neill (Kevin McKidd) is a police detective who is left reeling by the news that his own teenage daughter has disappeared. Then he is approached by a journalist who tells him to revisit the infamous unsolved case of missing local girl Julie Mackie because fatal mistakes were covered up. 

As Chris re-examines the case, he uncovers a long list of errors and firm evidence of wrongdoing. Meanwhile, his wife Michelle (Vinette Robinson), a former undercover officer, decides to take matters into her own hands and find their daughter herself. But the clues expose the close ties between the criminal underworld and those at the very top of the political establishment. 

But just as Chris and Michelle get close to the truth another girl goes missing — this time the daughter of the Justice Minister who was on the brink of an election victory. The kidnap has striking similarities to Julie Mackie’s case, so is the past repeating itself? 

Six Four cast — Kevin McKidd as Chris O’Neill

Kevin McKidd plays police detective Chris McNeil whose teenage daughter disappears. 

Kevin played Tommy in the 1996 film Trainspotting and went on to star as Count Vronsky in the ITV series Anna Karenina. He’s also appeared in After Life, Rome, Percy Jackson & The Lightning Thief, Star Wars: Rebels and Station 19. Kevin is well known for his role as Dr Owen Hunt in Grey’s Anatomy

Kevin McKidd in Grey's Anatomy.

Kevin McKidd as Dr Owen Hunt in Grey's Anatomy. (Image credit: ABC/Sky)

Kevin McKidd in 1996 film Trainspotting alongside Ewan McGregor and Johnny Lee Miller.

Kevin McKidd (second from right) in 1996 film Trainspotting alongside Ewan McGregor and Johnny Lee Miller. (Image credit: Channel 4/Film Four)

Vinette Robinson as Michelle O’Neill

Vinette Robinson plays Chris' wife Michelle O’Neill whose equally frantic about her daughter going missing.

Vinette played Tracy in the 2003 series Between the Sheets. She’s since been in Hope Springs, Waterloo Road, Doctors and Sherlock. She starred as Nicola Daniels in The A Word and played civil rights campaigner Rosa Parks in an episode of Doctor Who. She’s also had roles in A Christmas Carol, Star Wars: The Rise of Skywalker and the critically acclaimed movie Boiling Point with Stephen Graham. 

Vinette Robinson plays Michelle O’Neill in Six Four.

Vinette Robinson plays Michelle O’Neill in Six Four.  (Image credit: Getty)

Vinette Robinson as Rosa Parks in Doctor Who.

Vinette Robinson as Rosa Parks in Doctor Who. (Image credit: BBC)

Who else is starring in Six Four? 

The Six Four cast also includes Richard Coyle (Fantastic Beasts: The Secrets of Dumbledore), James Cosmo (The Bay), Alex Ferns (EastEnders, Danny Boy) plus newcomers Iona Anderson, Andrew O’Neill and Nilani Chetty.

Alex Ferns (on far right) in Danny Boy.

SIx Four star Alex Ferns (on far right) in Danny Boy. (Image credit: Gareth King (BBC).)

Is there a trailer for Six Four? 

Not yet but keep an eye on this page and if a Six Four trailer is released by ITV, we’ll post it on here. 

Nicholas Cannon
Nicholas Cannon

I'm a huge fan of television so I really have found the perfect job, as I've been writing about TV shows, films and interviewing major television, film and sports stars for over 25 years. I'm currently TV Content Director on What's On TV, TV Times, TV and Satellite Week magazines plus Whattowatch.com. I previously worked on Woman and Woman's Own in the 1990s. Outside of work I swim every morning, support Charlton Athletic football club and get nostalgic about TV shows Cagney & Lacey, I Claudius, Dallas and Tenko. I'm totally on top of everything good coming up too.