At first glance, DEPT. Q opens like a conventional crime drama. But from the very first scene, the series, created by Scott Frank and based on Jussi Adler-Olsen’s gripping novels, twists expectations. With a brooding setting in Edinburgh and characters haunted by past traumas, the show quickly becomes an intricate psychological maze. At the center of this chilling journey stands Detective Chief Inspector Carl Morck (Mathew Goode), a gruff, wounded man pulled into a case far more disturbing than he expected.
Freshly returned to work after a traumatic shooting that left his partner, DS Hardy (Jamie Sives), paralyzed and another officer dead, Morck is shoved into the basement office of a new “cold case” unit to keep him out of trouble. But trouble finds him anyway. With Hardy reluctantly by his side, and joined by Syrian investigator Akram (Alexej Manvelov) and emotionally scarred constable Rose (Leah Byrne), Morck dives into his first reopened case—a case that begins with a disappearance and ends in the belly of generational trauma and madness.
THE MYSTERY OF MERRITT LINGARD
Merritt Lingard (Chloe Pirrie), a prominent prosecutor in Edinburgh, vanishes without a trace. She had recently been involved in a controversial case accusing a powerful man of murdering his wife. As the cold case team starts digging, they unearth threads that lead to a small town named Mohr, long-forgotten police reports, and a family with an ugly history: the Jennings.
Clive and Ailsa Jennings had two sons, Harry and Lyle. Clive, once the CEO of Shorebird Ocean Systems, was a tyrant whose legacy of abuse was centered on a hyperbaric chamber used for deep-sea divers. Their mentally unstable mother, Ailsa, used it as a torture device. Harry endured the punishment. Lyle, younger and more fragile, broke under it. When Ailsa later killed Clive by setting their house on fire and framing Lyle, it only worsened his unraveling mental state.
While Ailsa was institutionalized, Harry plotted an escape from the dysfunction with Merritt. During a robbery at the Lingard home, Lyle nearly beat William Lingard to death until Harry stopped him. What happened next remained shrouded in ambiguity: Harry tried to escape but ended up dead. Whether he was murdered by Lyle in a fit of rage or died accidentally during the escape attempt is never definitively answered. Merritt, possibly unaware of Lyle’s involvement in the attack on William, may have assumed Harry was the assailant.
LYLE’S DESCENT INTO MADNESS
Lyle’s path only darkened. After Harry’s death, Ailsa’s abuse escalated. Lyle was institutionalized at Godhaven, where he met Sam Haig, a young boy who bore an uncanny resemblance to Harry. Haig’s presence reignited Lyle’s trauma. Years later, Lyle reunited with his mother and started working at a ferry company in Mohr. Meanwhile, Haig became a successful journalist.
Haig, attempting to make amends for a past fight, found Lyle and apologized for injuring his eye. But instead of forgiveness, Lyle saw a threat. He murdered Haig in a staged climbing accident and assumed his identity. The motive? To infiltrate Merritt’s life, avenge Harry’s death, and make Merritt confess to a crime she never committed.
MERRITT’S CAPTIVITY AND THE FOUR-YEAR NIGHTMARE
As “Sam Haig,” Lyle seduced Merritt during a vulnerable period in her life. Slowly, he manipulated her into returning to Mohr. Rather than abducting her outright, Lyle spent time crafting an emotional bond, perhaps fulfilling a twisted fantasy of living Harry’s life with her. Eventually, on a ferry to Mohr, he kidnapped her and delivered her to Ailsa. The pair held Merritt captive for four years, demanding a confession that never came.
Merritt made a desperate attempt to escape and injured Ailsa in the process. She even managed to dial 999 before being shoved back into the hyperbaric chamber. As fate would have it, Constable Cunningham, investigating Mohr, stumbled upon the Jennings property. He found Merritt alive but imprisoned. Before he could call for backup, Lyle killed him and concealed his body in a police car hidden in the warehouse near the chamber.
DEPT. Q ENDING EXPLAINED
Back in Edinburgh, William Lingard had begun piecing together clues. He recognized Lyle—not only as the man who nearly killed him years ago but also as the one last seen with Merritt on the ferry. This prompted Morck and Akram to head to the Jennings estate. There, they discovered Cunningham’s lifeless body and the imprisoned Merritt.
Using Hardy’s remote help, they stabilized the chamber’s pressure just in time to save Merritt. Lyle made a last-ditch attempt to intervene, but Morck and Akram overpowered and killed him. Ailsa, fleeing the scene, ultimately took her own life when cornered.
Merritt was finally rescued. Her reunion with William was tearful and tender, bringing a sliver of hope at the end of a harrowing ordeal.
WHAT DOES IT ALL MEAN?
The resolution of DEPT. Q’s first season isn’t just about solving a disappearance. It’s a descent into the generational trauma of the Jennings family, the cracks in the justice system, and the personal reckonings of every character involved. Lyle and Ailsa’s obsession with vengeance led to years of torture and pain. Their attempt to extract a false confession ended in complete destruction.
As for Merritt, surviving such cruelty wasn’t just a matter of physical endurance. Her time in captivity became a dark mirror reflecting past mistakes, particularly her actions in the Kirsty Atkins case. Whether she returns to her prosecutorial role remains uncertain, but it is clear she has been deeply changed by her ordeal.
Carl Morck, too, experiences transformation. What began as an unwanted assignment becomes a mission that reignites his purpose. Hardy, confined to a wheelchair and battling suicidal thoughts, finds renewed value in contributing to the case. Akram and Rose, both battling trauma, forge bonds and uncover strength within themselves.
