The thrilling third episode of "The Breakthrough" kicks off with Per and John presenting their proposal to use genealogical mapping to identify the elusive killer to their superiors. Per's request hinges on accessing family registries, prompting concerns among the officers about potential privacy violations. In response, John cites the notorious Golden State Killer case, which sways them to grant him a two-week window to crack the case before it's officially deemed cold.
The investigation commences, but Per encounters a significant hurdle: the DNA profile, generated using outdated 2004 technology, is severely lacking in detail. Dishearteningly, all available blood samples from the murder weapon have been exhausted in creating this incomplete profile. Impatient, John urges Per to proceed despite the limitations. A ray of hope emerges as Per uncovers three ancestral matches, all tracing back to Germany, with one residing in Linkoping.
Meanwhile, John encounters Gunilla's weary husband, attempting to offer reassurance. The weary old man, tired of the endless updates, tells John to only contact him if there is genuine progress. Disheartened, John pressures Per, demanding an international warrant to access the German registry and pushing him to make statements that can't be verified. Frustrated, Per withdraws from the pressure-cooker situation. Unable to pursue him further, John is summoned to an awkward meeting with his son, Henry, who remains distant and unengaged.
Back on the case, John turns to the forensics team, pleading for more DNA evidence. A technician spots a glimmer of hope in some overlooked DNA on the beanie. They vow to create a more robust DNA profile, reassuring John of their commitment.
Per retreats to his mundane routine, grappling with parenting challenges as his daughter, Klara, skips school. To his surprise, John awaits him, offering a heartfelt apology and promising to proceed with caution. Confessing that the case has taken a personal toll on him, John persuades Per to rejoin the investigation.
With the new, complete DNA profile in hand, Per uncovers over 800 potential matches related to the killer, igniting optimism within John's team.
Regrettably, the European Union's stringent data protection regulations have deemed Per's investigative technique unlawful. The official termination of his duties is impending, scheduled for the week's conclusion, and John urges Miran to remain oblivious to the impending news until then. Through meticulous scrutiny, Per manages to hone in on three potential matches in Ostergotland, convinced that the perpetrator holds ties to one of them.
Stina returns home amidst the sorrow of her father's passing, discovering he had meticulously preserved every one of her possessions. Among them, she stumbles upon her article about the sneak attack on John, now a subject of an ongoing investigation, sixteen years later, as her brother reveals. Intrigued, she delves deeper and learns of their employment of a genealogist, prompting immediate questioning about the legality of such actions.
Elsewhere, Francy encourages John to embrace life and not let the case consume him. He readily agrees to share a beer with her, during which she reveals that their children are friends and that Henry had inquired about the case's progress. John, taken aback, finds hope in Francy's suggestion that it's not too late to mend their relationship. Empowered, he leaves a voice message for Henry.
Stina's arrival interrupts John's thoughts, challenging him on the legality of Per's methods, which he chooses to disregard. Additionally, Miran receives his official dismissal notice. John pleads with him, earning a reprieve of two more days until Miran's return from a press conference. Believing they are on the cusp of a significant breakthrough, John persuades Stina to remain silent about the case in exchange for an exclusive story, which she reluctantly agrees to.
Per begins to hallucinate, lashing out at his colleagues. Concerned, John takes Per on a jog, sharing his own tale of sacrificing his athletic career by participating in a second Olympic event despite being injured. As "The Breakthrough Episode 3" draws to a close, John advises Per to take a well-deserved break.
