Episode 1: "The Skeleton Underground" – Cold Case Reopened & Bombing Background
At the renovation site of London’s central abandoned Aldwych Underground Station, an excavator’s bucket suddenly jammed as it broke through the concrete platform. When workers cleared the debris, a hunched male skeleton was exposed beside the tracks—a rusted steel rod protruding from his chest cavity. His left hand tightly clutched a worn 2005 London Underground ticket, with the faint words "King’s Cross Station" still visible on its surface. After bomb disposal experts ruled out the risk of WWII-era ordnance, the Cold Case Unit took over. Sunny Khan stood on the dusty platform, accompanied by a new face: his 28-year-old partner Zoe Taylor, a police officer recently transferred from the academy.
Forensic initial examination provided key details: the victim was a male aged 22-25, with an estimated time of death between July-August 2005 (supported by the ticket’s validity and a pair of 2005 summer-style sneakers found near the skeleton). The fatal wound was a steel rod piercing his lung, and there were signs of struggle before death. Most notably, the victim had a tattoo on his right arm—a blue character for "Freedom" that had been slashed with a knife, seemingly an attempt by the killer to hide his identity. "The summer of 2005 is most memorable for Londoners because of the 7/7 Bombings," Sunny wiped the subway ticket and said to Zoe. "Could he have been a bombing victim, mistakenly buried here?"
Archive searches focused on missing persons after the 2005 bombings. Sunny spent two days in the London Police’s microfilm library and found a missing person report labeled "Suspected Bombing Victim": 24-year-old freelance photographer Jake Carter, who had disappeared on July 8, 2005 (the day after the bombings) after departing from King’s Cross Station. His mother Martha had submitted DNA samples three times, but no match was found due to "fragmented remains at the bombing site." In the student ID photo attached to the report, Jake’s right arm clearly showed the "Freedom" tattoo—matching the skeleton’s features exactly.
When Sunny found Martha, the elderly woman lived in a small apartment in suburban London, her walls covered with Jake’s photography—mostly street scenes of London before the 2005 bombings. At the news of the "skeleton," the photo frame in Martha’s hand clattered to the carpet, cracking the image of Jake’s smile. "They said he died in the bombings, that we’d never find his remains… turns out he was trapped in that subway station all this time," she said, trembling as she offered Jake’s toothbrush for DNA testing. "Before he disappeared, he said he was going to photograph ‘the truth after the bombings’ and mentioned ‘someone was profiting from the disaster.’ I thought he was just overreacting then."
Zoe’s impetuosity emerged early in the episode: she argued they should prioritize checking bombing victim identification records, "it might just be a case of misidentified identity," while Sunny insisted on delving into Jake’s "truth investigation." "Cold cases aren’t about speed—they’re about details," Sunny pointed to Jake’s photography diary. "The last photo he took has a blurry shot of the insurance counter at King’s Cross Station, which matches the starting point on the subway ticket." The episode ends with forensics confirming the skeleton is Jake, and trace amounts of blue ink found in the folds of the subway ticket—matching the ink composition of a 2005 insurance company’s promotional brochures, suggesting Jake’s death was linked to insurance.
Episode 2: "Traces of Fraud" – Suspects Emerge & Family Dilemmas
Following the "insurance" lead, Sunny and Zoe quickly identified "Integrity Insurance Brokers"—a company near King’s Cross Station in 2005. Jake had visited the firm multiple times regarding "bombing victim claims" before his disappearance. The company’s founder, Alan White, is now a senior executive in London’s insurance industry. When Sunny mentioned "Jake Carter," Alan’s hand clutching his coffee cup tightened suddenly, spilling brown liquid onto his tailored suit. "I can’t remember this person—there were too many claims after the 2005 bombings; we were swamped," he said. But Zoe noticed a 2005 staff handbook hidden in his desk drawer, with "Jake Carter" crossed out in black ink and "Resigned" written beside it.
More suspects gradually emerged:
Ben Miller, Jake’s college classmate and 2005 roommate, now runs a photography studio. He admitted to a dispute with Jake over "borrowed money" back then: "Jake said he was going to expose a big scam and told me to stay out of it. I thought he was crazy at the time."
Lucy Green, a former employee of Integrity Insurance who resigned suddenly in August 2005, now lives in Edinburgh. She hesitated on the phone for a long time: "Jake asked about ‘double claims’—he said some clients were defrauding insurance using the identities of bombing victims. I told him not to meddle; Alan has powerful connections."
Sunny’s family troubles intensified in this episode: his daughter Lena was bullied at the University of London, where rumors spread that "her father is a ‘cold-blooded detective’ who only cares about the dead, not her." Lena locked herself in her dorm and refused to attend classes. Sunny drove to the university late at night and waited outside the dorm until midnight, when Lena finally emerged with red eyes: "You’re always working on cases. Where were you when I was being bullied?" Sunny hugged his daughter, his throat tight: "I’m sorry I let you down. But this case is about a young man around your age, and his mother is also waiting for answers."
Conflict between Zoe and Sunny erupted during the investigation: Zoe had summoned Ben Miller without authorization and questioned him aggressively, causing Ben to lose his temper and refuse to cooperate. "You’re destroying evidence!" Sunny snapped at Zoe in the police station corridor. "Jake’s death might involve more people—we need trust, not threats." Zoe fell silent for a moment, then pulled out her notebook: "My sister died in the 2005 bombings. I’ve always wondered if there are people like her who don’t even get the dignity of being remembered." Her past moved Sunny, and the two finally reached an understanding: "Let’s find the truth—for Jake, and for your sister."
The episode ends with Lucy Green suddenly contacting Sunny, saying she wanted to hand over "something Jake left behind." However, she was involved in a car accident on her way to the meeting. The police initially ruled it an "accident," but Sunny stared at the scattered 2005 insurance documents at the crash scene, his expression grave: "This wasn’t an accident. Someone didn’t want her to talk."
Episode 3: "The Diary’s Secret" – Clues Connected & Conspiracy Outline
The third episode centers on "Lucy’s car accident" and "Jake’s diary." Sunny found a metal box hidden in the floorboards of Lucy’s apartment, containing Jake’s black leather-bound diary. Entries from July 2005 detailed his findings: Alan White had exploited the chaos of the London 7/7 Bombings to forge the identities of 12 "victims," defrauding insurance companies of over £500,000 in total claims. Ben Miller had been responsible for taking "fake photos of the victims’ lives," while Lucy had helped alter insurance system data.
The most crucial page in the diary had a blurry surveillance screenshot attached: dated July 8, 2005, it showed Jake taking a photo of Alan arguing with a hat-wearing man outside the insurance counter at King’s Cross Station. A note beside it read: "Third accomplice, in charge of ‘handling troubles.’" "This man is probably Jake’s killer," Zoe pointed at the screenshot. "The subway ticket Jake was holding was for a trip from King’s Cross Station that day. He must have followed this man to the abandoned subway station, then was silenced."
Sunny summoned Ben Miller again, this time bringing Jake’s diary and Lucy’s accident report. "Lucy is dead—you could be next," Sunny’s voice was calm but firm. "Jake told you to stay out of it because he was protecting you. Are you still going to cover for Alan?" Ben’s resolve crumbled. He broke down crying and admitted: "Alan tricked Jake into thinking they’d ‘cooperate to expose the fraud,’ luring him to the abandoned subway station… I didn’t take part in the killing, but I saw Alan’s man stab Jake with a steel rod and slash his tattoo." Ben also revealed that the "hat-wearing man" was Alan’s bodyguard Tommy, who had suddenly "disappeared" in September 2005.
Zoe investigated Lucy’s car accident and discovered the owner of the at-fault vehicle was a "shell company," with funds traced to Alan’s overseas accounts. "He’s trying to eliminate all witnesses," Zoe slapped the evidence down in front of Sunny. "We need to find Tommy quickly, or he’ll be silenced too."
Sunny’s family issues also took a turn for the better: he took Lena to Jake’s photography exhibition (held by Martha in memory of her son). Looking at the photos Jake had taken of post-bombing reconstruction on the walls, Lena said softly: "I used to think you ignored me for cases, but now I know—you’re helping them find their way home." She volunteered to help Sunny organize Jake’s diary and found Tommy’s old address in one entry: an abandoned factory in East London.
The episode ends with Sunny and Zoe arriving at the factory, only to find scattered cigarette butts and a torn 2005 insurance policy—Tommy was nowhere to be seen. In Alan’s office, he was burning a pile of documents, a sneer on his lips, and a plane ticket to a foreign country on the corner of his desk. Sunny stood at the factory entrance, clutching Jake’s diary: "He can’t run. We’ve already touched the root of this fraud network."
Core Themes & Suspense Setup
The first three episodes of Season 5 deeply tie the cold case to "post-disaster human alienation," using the 2005 London 7/7 Bombings as historical context. Alan exploited the chaos of the disaster for profit, Ben chose silence out of fear, Lucy tried to make amends in guilt, and Jake sacrificed his life for the truth—their choices together form a "portrait of humanity" under the shadow of disaster. The series no longer focuses solely on "who the killer is," but also asks "how disasters amplify greed and cowardice," turning the cold case into a window to reflect on historical trauma.
Another core focus is the protagonists’ growth and collaboration: Sunny finds a new balance between family and work, evolving from a "case-obsessed detective" to a "listening father and partner"; Zoe, once an impulsive newcomer "investigating with personal obsession," learns to respect clues and humanity. Their collaborative journey adds a layer of warm teamwork to "cold case investigation."
In terms of suspense, two key foreshadows are planted in this phase: first, Tommy’s whereabouts—he is the only witness who saw the killer and the key to exposing the fraud network; second, the "12 forged victims" mentioned in Jake’s diary—only 3 have been verified so far, and the identities and families of the remaining 9 remain unaccounted for, suggesting the fraud is far larger than imagined. These clues lay the groundwork for the "network-style investigation" in subsequent episodes and continue Unforgotten’s core premise that "behind cold cases lies an even greater truth."