Episode 3 of "Under a Dark Sun" opens with haunting flashbacks, painting a vivid picture of Dimitri and Alba in a compromising embrace, lost in the throes of drug-induced euphoria, with little Leo, an innocent babe in arms. Upon returning home, Alba's world shatters as she discovers Dimitri unconscious, a needle still lodged in his arm. The ensuing altercation escalates until Dimitri storms onto the balcony seeking solace from the heated exchange. Alba, frozen in horror, can only speculate on the harrowing possibility that he voluntarily plunged to his death, thereby framing her for a crime she didn't commit. Throughout, Alba's unwavering mission has been to shield her son from harm, making her current decision to entrust him to a deceitful adversary an excruciating dilemma.
Back at their shared abode, a pall of worry settles as Noor's absence stretches into a mysterious disappearance. Whispers circulate that Mathieu was seen loitering nearby one fateful morning, hinting at a possible abduction. Noor's lack of documentation further confines her options, rendering escape unlikely.
Mathieu, unperturbed by the turmoil, seeks out Beatrice to confess his comprehension of her seething anger. He reveals a renewed plan to confront Omar and reclaim their perfume venture, but his optimism is short-lived. Upon witnessing scorched fields and missing roses—remnants of Beatrice and Alba's earlier turf war—Mathieu confronts Valentin with a fiery intensity, ultimately terminating his employment. Asserting his dominance unequivocally, Mathieu orders Valentin to vacate the premises forthwith.
Lucie is taken aback by Mathieu's high-handed behavior and confronts him, expressing her dismay. Meanwhile, a bombshell drops as the murder weapon surfaces, linked to Alba’s residence via an anonymous tip-off to the authorities. Intriguingly, a thorough search, conducted during Alba’s absence, uncovers nothing incriminating. The mystery deepens as it transpires that Leo, entangled in a fragile relationship with his mother, possesses the weapon. Initial suspicions that Leo might have orchestrated the tip-off falter amid their strained dynamics. The specter of Dimitri's tragic demise looms large, casting a dark shadow over their bond.
Manon, a voice of reason, urges Alba to unburden Leo with the truth. Yet, for a mother who has dedicated her life to shielding her son, confessing the gravity of her past is an almost insurmountable challenge.
Back at the farm, the decision to rehire Valentin proved to be a colossal misstep for the family. He aids Alba in breaking into Mathieu's car, where they scrutinize the satellite navigation system together. Scanning through its history, they uncover that Mathieu was in the forest at an unearthly hour of 3 a.m. Alba, driven by curiosity, is dead set on uncovering the mystery behind this peculiar timing, and this time, she has Valentin by her side in this quest.
As Alba and Valentin delve deeper into the truth, Beatrice succumbs to her gambling addiction once again, heading to the casino to wager even greater sums of money, landing herself in a pickle. It transpires that the hidden 100,000-euro debt is actually Beatrice's, accumulated from her previous gambling binges. The casino revealed this information to Arnaud, who was left in utter disbelief. Jacques, the lawyer, had secretly given Arnaud the money to settle this debt, keeping Beatrice in the dark about it all along. Arnaud didn't want to saddle Beatrice with this burden, nor did he wish to confide in her about his illegitimate child.
Alba and Valentin trace the GPS coordinates to a clandestine house, furnished with a bed, a DVD player, and an assortment of cameras. It becomes evident that whoever has been spying on them has been up to no good. The tape contains distressing footage of a girl being abused, though mercifully, it cuts off before anything graphic is shown.
As they venture outside, realizing they are being watched through the camera, Lucas, the junior officer from earlier, aims his gun at them. Tragically, he is gunned down by an unidentified assailant, who then turns his weapon on Alba and Valentin. The pair scramble for safety, but their prospects look grim.
When Alba is reunited with Leo, she is startled to find Thierry waiting there alongside Manon. Leo has made the heart-wrenching decision to live with Thierry, fearful of Alba and distrustful of her intentions.
That evening, Lucie breaks the news to Mathieu that she intends to move in with her boyfriend in London. Having earlier confessed the truth about Arnaud's demise to him, she feels compelled to take the plunge. Jacques and Beatrice then make an appearance, announcing their engagement.
When Alba storms into the police station, intent on spilling what she knows, she encounters a hurdle. She receives a menacing anonymous text, warning her to keep quiet. If she refuses, her son's life will be in jeopardy.
