Episode 3 of Anthracite kicks off with Solel interrogating students about Roxane's whereabouts, only to be interrupted by a shocking event - someone stabbing Juliette. Following the trail of blood, he stumbles upon an unexpected figure, accompanied by a warped cross reflecting in the mirror.
Meanwhile, Gio trails Denis to Caleb's house, where a chilling revelation awaits. Denis rips apart a mural to reveal the lifeless body of Derekov. There's no masked man, as Denis confesses to hallucinating the entire ordeal. It turns out he's the masked figure who stoned Derekov in a flashback, later poisoning Caleb's household water supply, causing the deaths of all cult members.
Denis claims Caleb manipulated him into committing these atrocities with the promise of curing his dementia. However, in a moment of confusion, he poisoned the festival's water supply, mistakenly believing it was the cult's. Denis insists he had no part in Roxane or Emma's demise.
Elsewhere, Ida and Jaro return home to discover Anais has vanished, leaving her hotel room in ruins. Out of compassion, Jaro offers her a place to crash. While preparing the guest room, Claude hands Jaro a recording of Juliette singing, and the pair share a moment of sadness.
The Police Captain is enraged by the poisoning and suspends Gio, instructing Erwan to take over and wrap up the case, pinning the murders on Denis. In a moment of candor, the Captain reveals that Erwan desires to transfer Gio to Brittany, leaving her devastated.
Finally, Solal awakes to a nightmarish discovery - one of his legs is missing, leaving him shocked and disoriented.
Ida, helplessly stranded in her room, ultimately sought comfort in Jaro's arms, craving an endorphin injection to soothe her troubled mind. Her search resumed with renewed vigor, but her path crossed with Jaro's aunt, Marie, downstairs. Marie's warnings rang in her ears, cautioning her against unearthing a sordid chapter of ancient history. She sternly admonished Ida not to disrupt Jaro's life, as he had been granted a second chance to rectify his mistakes.
Meanwhile, as Anais checked out of her hotel, a mysterious figure approached Malia, branding her face with the same distorted cross symbol. Malia screamed in terror, and when Anais discovered her, she described the assailant as a monster. Elsewhere, Ida crept into Denis' house alone, unearthing details of an unfinished condo before encountering Gio. Her presence was unwanted, and her impromptu concert in the car only added to Gio's irritation.
Anais promptly informed Jaro of the incident, and he dashed to her side. She handed him the drawing of the symbol but refused to linger any longer. Jaro vowed to track down the perpetrator and delved into Solal's tapes until he stumbled upon one bearing the identical symbol.
The girls arrived at the condo and were startled to find the walls adorned with intricate math formulas. They realized that Denis had been hiding someone within these walls. Outside, they encountered a ranger whose suspicious behavior drew Gio's scrutiny. Before he could threaten them into leaving, Ida stunned him with a taser, much to Gio's astonishment.
At the ski shop, Eddy, a thug from Paris, appeared in search of Jaro. Romeo, with the assistance of his dog, Brad, forcibly evicted Eddy. But Eddy's vengeance was swift and brutal; he shot Brad, leaving Romeo devastated. Romeo rushed Brad to Hari, who, despite not being a vet, offered whatever assistance he could. Once Brad's condition stabilized, Hari's concern shifted to Romeo, who returned his affection with a tender kiss. Yet, Romeo pulled away, urging Hari to leave.
In the storage room, Jaro watched the tape, which revealed a chilling flashback. It showed someone stabbing Juliette, and the perpetrator was revealed to be a female student named Detraz. Convinced that she was the one who targeted Malia, Jaro left a voicemail for Ida. As he exited, he was tailed by an unknown figure, but Erwan intervened, escorting him safely to the station.
He firmly believes that Jaro is culpable for Emma's grisly murder and insists on administering a drug test. As Jaro heads towards the washroom, his eyes fall upon Denis' dusty old files, and he singles out Detraz's. Detraz, the pastor's daughter, was once a vocal opponent of the cult members, bearing a distinctive scar across her face and always adorned with a twisted cross necklace. Jaro hurriedly informs Romeo of his discovery, revealing that Detraz is an eccentric recluse who dwells solitary in the mountains. They decide to embark on a journey to seek her out.
Meanwhile, Ida and Gio are eager to unravel the ranger's secrets and stumble upon a tent filled with lifeless sheep carcasses. Suddenly, they are overcome by a powerful drug, and individuals clad in yellow suits materialize. Inside the asylum, it's time for the patients to take their pills. Caleb discreetly signals to a fellow inmate, who feigns a seizure, allowing him to discard his medication.
As they make their way to Detraz's abode, Eddy unexpectedly slams into Romeo's car. He viciously pushes them over the precipice and opens fire, but the boys manage to evade his bullets. They flee, racing through the countryside until they finally stumble upon Detraz's secluded house. Inside the bedroom, they are startled to find Solal. They quickly load him into Detraz's car, but before they can make their escape, the woman herself arrives, rifle in hand, bringing Anthracite Episode 3 to a thrilling climax.
