‘Dept. Q’s Most Twisted Moment Makes It Netflix’s Latest Must-Watch Detective Series

Editor’s Note: The following contains major spoilers for Season 1 of Dept. Q.Netflix’s Dept. Q is the kind of detective drama that thrives on slow-burn tension, layered mysteries, and emotionally complex characters. Adapted from the bestselling Danish book series by Jussi Adler-Olsen by The Queen’s Gambit creator Scott Frank, the series follows DCI Carl Mørck (Matthew Goode) and his newly formed cold case unit as they investigate long-forgotten cases. The first season centers on their first assignment: the disappearance of prosecutor Merritt Lingard (Chloe Pirrie).

As Carl and his team reopen the investigation, viewers also see that Merritt is alive, being held captive and tortured after vanishing four years earlier. While the central mystery revolves around who took Merritt and why, flashbacks to her past gradually reveal unsettling connections. When the truth is finally uncovered, it exposes a deeply rooted, personal vendetta that elevates Dept. Q beyond the typical crime thriller, cementing it as a must-watch in the genre.

Merritt’s Abduction in ‘Dept. Q’ Is Completely Personal

As Carl and his partner Akram (Alexej Manvelov) dig into Merritt’s past, they uncover a trail that leads to a man Merritt was romantically involved with shortly before her disappearance: journalist Sam Haig. He had approached Merritt with explosive documents that linked several of her colleagues to a corruption scandal. However, their investigation quickly hits a dead end when they discover that Haig died in a climbing accident, and the timeline surrounding his final days doesn’t align with what they’re being told.

Digging deeper, Carl and Akram discover that while Haig was supposedly in a relationship with Merritt, he was actually involved in an affair with his best friend’s wife in a completely different city at the same time. The logistics don’t add up, leading them to a disturbing realization: the “Haig” Merritt had been seeing was an impostor. Someone had catfished her, stealing Haig’s identity to get close to her, but they have yet to know why.

The impostor is eventually revealed to be Lyle Jennings, a man harboring a long-held personal grudge against Merritt. In a flashback in Episode 9, Lyle murders the real Sam Haig at a rock climbing center, staging the death to look like an accident. He steals Haig’s belongings and begins his calculated pursuit of Merritt. For four years, Merritt has been held in captivity, her abduction carefully orchestrated by someone who knew exactly how to get to her.

Who Is Lyle Jennings in ‘Dept. Q’?

Through a series of haunting flashbacks, we learn about Merritt’s history with Lyle’s older brother, Harry. As teenagers, Merritt and Harry shared a close bond and planned to run away together to escape their small town. But things took a dark turn when Harry broke into the Lingard house to steal jewelry to fund their escape. He was mistaken for an intruder by Merritt’s brother William (Tom Bulpett), who attacked him. In retaliation, Lyle assaulted William, leaving him in a coma with permanent brain damage. Harry, trying to flee the consequences, died while running from the police.

In Episode 7, Carl and his team uncover that Haig had spent time at a juvenile corrections institute called Godhaven and had recently returned to the area to research a book. This detail leads to a key discovery in Episode 9: Lyle Jennings also spent time at Godhaven and had known Haig personally and was close to him. That connection gave Lyle both motive and opportunity. He saw Haig as the perfect target for identity theft and a tool for carrying out his plan of revenge.

For years, Lyle and his mother, Ailsa, blamed Merritt for Harry’s death. Their grief morphed into obsession, leading them to abduct Merritt and hold her in a hyperbaric chamber for four years. The real twist isn’t just that Merritt was catfished by someone dangerous, but that she was targeted by someone from her past. During her captivity, Merritt spends years racking her brain, believing that she was taken by someone angry over a prosecutorial decision. The reveal that it all stemmed from a personal grudge makes the story even more devastating.

The Twisted Reveal in ‘Dept. Q’ Makes It an Impressive Crime Drama

The twist at the heart of Dept. Q’s first season elevates it far beyond a typical crime drama. By the time the full truth about Lyle Jennings is revealed, the show has pulled viewers into a story about grief, justice, and the dangerous ways trauma can manifest when left unresolved. Carl is still reeling from the guilt of what happened to his former partner, James Hardy (Jamie Sives), in a shooting that left him paralyzed. Meanwhile, Lyle and his mother are consumed by their own grief that turns into something much more destructive.

What makes this twist so effective is that it isn’t gratuitous. While it heightens the stakes and drives the plot forward, it’s deeply rooted in character. Like much of the show, the reveal serves as an emotional turning point, not just a narrative one. It’s devastating not only because of what happened to Merritt, but because of what it exposes about everyone involved. Lyle represents what happens when pain turns into obsession, when grief is weaponized in pursuit of revenge, and he’s willing to destroy anyone in his path to satisfy it.

By reframing the central investigation through this lens, Dept. Q becomes a character-driven drama about the fragility of justice and the lasting cost of unhealed wounds. That emotional depth is what sets it apart, transforming it into one of Netflix’s most resonant detective dramas. It’s not just about who did it, but why, as well as what that reveals about the people involved, the system they serve, and the trauma that lingers long after the case is closed. For fans of shows like Broadchurch, The Fall, or Mindhunter, Dept. Q delivers a similar level of quality, but with a distinctive emotional resonance. It’s no surprise the series has earned high praise and strong ratings, not just for its shocking twist, but for its thoughtful storytelling and complex, layered characters, making it a must-watch.