Meanwhile, Duncan’s (Mark Bonnar) subplot regarding the stolen boat money might feel like padding, but it serves a purpose: it shows how ordinary lies metastasize. By episode’s end, Duncan’s small betrayal forces Perez to lie to a witness—a professional sin that will surely return.

Perez is haunted. Not by ghosts—by guilt. His confrontation with Alice (the grieving mother of one of Malone’s victims) is the episode’s brutal heart. She doesn’t scream or cry. She whispers: “You’re not here to find who killed him, Jimmy. You’re here to find who did the world a favour.” Henshall’s performance is a study in containment—his jaw tightens, his eyes drop. He knows she’s right.

By the final shot—Perez staring out at the North Sea, Malone’s file in his hand, unclosed—you realize the real crime isn’t the murder. It’s the system that made the murder feel inevitable.

The reveal, while emotionally devastating, arrives via a piece of exposition that feels slightly rushed—a sudden memory from a minor character that unlocks everything. Given the show’s usual patient unspooling of clues, this moment clunks. It’s the episode’s only misstep, but it’s a noticeable one.

The writers (led by David Kane) pull off a neat trick. For forty minutes, all evidence points to Sally McColl (a standout guest turn by Anneika Rose), the prison nurse who befriended Malone. Her alibi crumbles; her laptop contains searches for untraceable poisons. Tosh pushes for arrest.

What makes this episode exceptional is how it refuses to separate the investigation from the investigators’ inner lives.

The episode opens not with action, but with the haunting stillness of a Lerwick dawn. Cinematographer Simon Miller continues his masterclass in atmosphere: the grey, pregnant sky hangs over the peat-stained water like a held breath. It’s a visual metaphor for the community itself—clenched, waiting.