ITV’s Forgotten Four-Part Scottish Crime Thriller Six Four Is a Dark, Addictive Mystery That Feels Like a Scandi-Noir
Just four episodes. That is all it takes for Six Four to pull viewers into a disturbing Scottish crime mystery where missing children, buried secrets and police corruption become dangerously intertwined. With its bleak atmosphere, gripping performances and steadily escalating suspicion, this ITV thriller delivers the kind of unsettling tension that makes Scandinavian crime dramas so compelling.
Originally released on ITVX on March 30, 2023, the four-part series stars Kevin McKidd and Vinette Robinson as a married couple whose lives unravel when their teenage daughter disappears.
Set primarily in Glasgow, the drama begins with a family’s desperate search for answers before expanding into a complicated investigation involving a notorious unsolved case, powerful individuals and long-concealed wrongdoing.
Inspired by Hideo Yokoyama’s bestselling Japanese novel of the same name, Six Four offers a distinctly Scottish interpretation of the crime story.
What Is Six Four About?
At the centre of the series is Chris O’Neill, a serving police detective played by Kevin McKidd.
Chris is already struggling with a deeply personal crisis when his teenage daughter, Olivia, goes missing.
As he attempts to understand what happened to her, a journalist approaches him with troubling information about another disappearance.
Years earlier, a young girl named Julie Mackie vanished in a case that became notorious within the police force.
The investigation was never successfully resolved, and the journalist now claims that serious mistakes were concealed by those responsible.
Chris begins looking into the old case, uncovering evidence of errors, corruption and professional ambition.
Meanwhile, his wife Michelle, played by Vinette Robinson, refuses to wait for the authorities to find their daughter.
A former undercover police officer, Michelle draws upon her previous experience to pursue her own investigation.
Her search takes her back towards a dangerous criminal world connected to her past.
As husband and wife follow different leads, the circumstances surrounding their daughter’s disappearance become increasingly complicated.
And when another high-profile kidnapping occurs, similarities to the historical Julie Mackie case suggest that the two investigations may be connected.
A Scottish Thriller With a Distinctly Nordic Noir Atmosphere

Although Six Four is firmly rooted in Scotland, its atmosphere has many of the qualities associated with Scandinavian crime dramas.
The story unfolds against a sombre urban backdrop, where the tension comes as much from the characters’ hidden motives as from the crimes themselves.
Rather than presenting a straightforward police investigation, the series gradually reveals how institutions, personal relationships and past decisions may be connected.
The mystery becomes increasingly unsettling as Chris discovers that the people responsible for uncovering the truth may have reasons to conceal it.
Michelle’s storyline adds another layer of danger, forcing her to confront elements of a previous life she had hoped to leave behind.
This combination of psychological tension, moral uncertainty and institutional corruption gives the series its distinctive appeal.
For viewers who enjoy dark, character-driven crime stories, Six Four offers an absorbing alternative to more conventional detective dramas.

Kevin McKidd Leads an Impressive Cast
Kevin McKidd, widely recognised for his role as Owen Hunt in Grey’s Anatomy, takes on the central role of Chris O’Neill.
His character is caught between his responsibilities as a police officer and his desperation as a father.
As Chris investigates the historical disappearance, he faces uncomfortable questions about the organisation he serves.
Vinette Robinson, known for Boiling Point, Sherlock and The A Word, plays his wife Michelle.
Unlike Chris, Michelle has experience working undercover, and her determination to find Olivia pushes her towards increasingly dangerous decisions.
The supporting cast includes James Cosmo, Alex Ferns, Richard Coyle and Lorne MacFadyen.
Together, the performers bring depth to a story that examines the emotional consequences of crime alongside the search for justice.
Based on a Bestselling Japanese Crime Novel
One of the most interesting aspects of Six Four is its literary origin.
The drama is inspired by the bestselling novel written by Japanese author Hideo Yokoyama.
However, the television adaptation moves the story from Japan to Scotland, giving the narrative a different cultural and geographical setting.
The series was created by BAFTA Scotland Award-winning screenwriter Gregory Burke, whose previous work includes Black Watch.
Ben A. Williams, known for his work on Sherwood and Baghdad Central, directed the four episodes.
The production was handled by House Productions, the company behind acclaimed British television projects including Sherwood.
Rather than simply reproducing the original novel’s setting, the adaptation uses Glasgow and Scotland’s political and policing environment to explore the story’s central themes of corruption, loyalty and betrayal.
Four Episodes Packed With Suspicion and Unanswered Questions
Unlike crime dramas that stretch their mysteries across numerous seasons, Six Four tells its story in just four instalments.
The opening episode establishes the disappearance of Chris and Michelle’s daughter while introducing the unresolved Julie Mackie investigation.
As Chris revisits the historical case, Michelle follows a separate trail connected to her undercover past.
Their searches gradually uncover more troubling information, while another kidnapping raises the possibility that events from years earlier are repeating themselves.
The limited episode count means the series can be watched over a single evening or a weekend.
Each instalment advances the central mystery while adding complications to the characters’ personal and professional relationships.
The result is a tightly contained thriller built around the question of who can be trusted when the truth threatens powerful interests.
Where Can You Watch Six Four?
All four episodes of Six Four were originally released on ITVX in the United Kingdom on March 30, 2023.
The series subsequently aired on ITV1, introducing the mystery to a wider television audience.
Viewers in the UK can look for the drama on ITVX, although streaming availability may vary by region and over time.
For anyone searching for a short crime thriller with a bleak atmosphere and an investigation filled with uncomfortable revelations, Six Four is worth considering.
Its combination of Scottish locations, strong central performances and a mystery involving corruption and betrayal gives it the feel of a Nordic noir without leaving Britain.
And with only four episodes to watch, this is a crime story that can easily consume an entire evening.