The Phenomenal 'Dept. Q' Ending Explained: Who Kidnapped Merritt Lingard?

I was an absolute monster fan of Netflix’s Matthew Goode detective mystery, Dept. Q, not just for the well-drawn characters but — and especially compared to something like Sara: Woman in the Shadows — for how incredibly well-developed the central case is. The detectives take a methodical, almost hypnotic approach to the mystery behind the disappearance of Merritt Lingard (Chloe Pirrie), meticulously building it over the course of nine episodes. It makes for terrific television and some of the best competence porn I’ve seen in a long while.

But, the case is a real humdinger — full of twists, red herrings, and an identity swap that could confuse anyone watching with only one eye. It’s not a show made for background viewing. If that’s how you watched it, you may have questions, particularly because the suspect list includes a number of criminals Merritt — a prosecutor — put away during her career. Here’s an explanation of that ending.

This guy kidnapped Merritt Lingard.

But who is this guy? He presents himself to Merritt in flashbacks as journalist and climbing hobbyist Sam Haig. Merritt and “Sam” had an affair, and the day after he abducted her and imprisoned her in a bunker-sized hyperbaric chamber for four years, Sam died in a climbing accident. So how could Sam have imprisoned Merritt if he was dead?

Because this man wasn’t actually Sam Haig. He was Lyle Jennings. Lyle posed as Sam Haig, carried on the affair with Merritt, abducted her, and then killed the real Sam Haig, staging it as a climbing accident.

But who is Lyle Jennings? He’s not one of the criminals Merritt put away. His connection to her preceded her legal career; in fact, Lyle was unintentionally the reason she became a prosecutor in the first place.

Back when Merritt was in her late teens, she and her brother, William, lived with their abusive father on the (fictional) Scottish island of Mhòr. Merritt was in a relationship with Lyle’s brother, Harry Jennings.

Merritt, angsty and desperate to escape the island, her family, and her past, jokingly suggested to Harry that they steal some of her late mother’s jewelry and run away together. But Harry — deeply in love with Merritt — took her seriously. While Merritt was away, he broke into her house to steal the jewelry, only to find that her brother William was still home.

Harry didn’t want to hurt William and likely would’ve backed off, but Lyle had followed him. Lyle, who had significant mental health issues (he would later meet the real Sam Haig in a psychiatric institution), violently attacked William and left him in a coma. William would suffer from intellectual disabilities for the rest of his life.

Devastated by what happened, Harry got drunk and took his own life by jumping off a ferry, the same ferry from which Lyle would abduct Merritt years later.

Years later, Harry and Lyle’s mother, Ailsa — who blamed Merritt for both Harry’s death and Lyle’s deterioration — orchestrated Merritt’s abduction. Lyle acted as her instrument of revenge. Fortunately, before they could kill Merritt, DCI Carl Mørck and the rest of Dept. Q cracked the case and rescued her. Lyle was killed in the process, and Ailsa took her own life before police could arrest her.

And that’s what happened to Merritt Lingard.

There is, however, one other major storyline involving Lord Advocate Stephen Burns (Mark Bonnar). This guy:

Dept. Q’s investigation into Merritt’s disappearance also uncovered that Stephen Burns, Merritt’s former supervisor, had pressured her not to call a key witness, Kristy Atkins, in the trial of Graham Finch, which opened the series. That omission led to Finch’s acquittal in the murder of his wife.

Ultimately, the Finch case wasn’t connected to Merritt’s abduction, but Morck leveraged the information to negotiate more funding for his department, a promotion for his partner, Akram (Alexej Manvelov), and a new car for himself.