Under a Dark Sun Ending Explained: Who Killed Arnaud?

Netflix’s French crime drama show ‘Under a Dark Sun’ revolves around an intriguing murder mystery that unravels the long-buried secrets of a wealthy family. Originally titled ‘Qui Sème le Vent,’ it follows the narrative of Alba, a single mother, who is on the run with her young son, Leo, to escape complications of her past. As such, she’s pleased to find quick employment as a flower picker at the illustrious Lasserre Estate. Nonetheless, the twist of fortune soon turns into a nightmare when the estate’s owner, Arnaud, mysteriously drops dead, framing Alba as the prime suspect. To make matters worse, his will and testament reveal the yet-unknown reality about his connection to the young woman as his biological father. Consequently, before she knows it, the mother is hurling down a cryptic spiral of family drama and death. SPOILERS AHEAD!

Under a Dark Sun Recap

The story begins with Alba Mazier fleeing from her family, who are trying to take custody of her young son, Leo, using her less-than-flattering past as legal leverage. The mother is dead-set on keeping her kid in her life by skipping town and relocating to Barcelona for a new start. For the same reason, she eagerly responds to an employment enquiry at Lasserre Estate. Even though the owner, Aranud, is initially reluctant to hire her, he relents and gives her a job as one of the many flower pickers in his fields. The position comes with accommodations at the campsite, which is a plus for the mother and her son. Nonetheless, it doesn’t take long for things to go sideways. Arnaud, still acting strange, calls Alba for a meeting at the fields before the arrival of the other flower pickers.

However, when Alba arrives for the meeting, she is only met with Arnaud’s dying corpse. Unwilling to get caught up in the mess, she bolts away from the premises to escape suspicion. Still, the head worker, Valentin, catches a glimpse of her, which brings the police to her door. Initially, she’s able to make her case, insisting that despite her incriminating presence at the crime scene, she has no real motive to murder the man. Yet, that defense flies out the window as soon as Arnaud’s will is disclosed. As it turns out, he has left his inheritance in equal parts to his heirs, which apparently includes Alba, his secret, illegitimate child. Even though the single mother seems to know nothing about this connection, the lead detective on the case remains suspicious of her. Fortunately, a saving grace falls on her lap in the form of Manon, Arnnaud’s granddaughter, who has a bone to pick with her family.

Manon, an attorney, appoints herself as Alba’s defense lawyer and begins helping her prove her innocence. The Lasserre family’s recent attempts to sell their estate despite their patriarch’s reluctance offer a different angle that casts them in a suspicious light. Nevertheless, it soon becomes evident that whoever is framing the latter for Arnaud’s murder isn’t concerned with playing fair. Over the course of the following days, Alba is put through hell as she discovers the family’s dirty secrets, such as worker exploitation and abuse. Furthermore, she falls victim to the elusive mastermind’s games when they kidnap Leo and force her to make fatal moves against the Lasserres. Eventually, in rescuing her son, she ends up discovering one of the people behind the plot against her.

Valentin, the field worker, who had formed a partnership with the mother, is actually a sex trafficker who is in cahoots with the murderer. However, he dies before he can reveal any insider information about the killer’s identity. On the other hand, power shifts in the Lasserre household as Lucie and Mathieu turn against their own mother, Beatrice, and trap her in a mental health clinic against her will. Nevertheless, the unpleasant trip leads to a startling revelation as the widow discovers Manon’s mother, Josephine, who had presumably abandoned the family, is actually a patient at the clinic. Simultaneously, Alba makes an unnerving discovery about her parentage. Ultimately, these two discoveries bring the single mother and her defense attorney to some discoveries about Arnaud’s death that shake up previously established conclusions.

Under a Dark Sun Ending: Who Killed Arnaud? Who Framed Alba?

From the get-go, Arnaud’s death remains the centerpiece to almost every other mystery surrounding Alba and the Lasserre family. Initially, the ones closest to him appear to be the ones with the most to gain from his death. His wife and kids are already vying for an opportunity to sell their rose fields to acclaimed perfumers and reap bags of benefits from the deal. Furthermore, with his apparent illegitimate heir and toxic relationship with his son, there is plenty of room for personal vendetta for Beatrice and Mathieu. The fact that Lucie finds a stashed gun at their estate is just the cherry on top that gives weight to this theory. Eventually, all of these signs end up explaining the truth about Arnaud’s murder, but in drastically unexpected ways. As it turns out, the patriarch was indeed killed by one of his family members: his granddaughter, Manon.

It all traces back to the red-haired woman at the psyche clinic: Josephine. She is Mathieu’s ex-wife and the mother of his children, Manon and Hadrien. So far, everyone assumed that the woman ran away from her family due to her husband’s constant infidelity and abuse. However, this wasn’t the whole truth. Josephine used to be an integral part of the Lasserre family and held sizeable shares and investments in their business. Therefore, Arnuad wasn’t happy to learn that she was thinking about divorcing Mathieu after discovering his affair with a flower picker. Consequently, the patriarch admitted his daughter-in-law into the psyche clinic and started gaslighting her into believing a different reality. Soon enough, this took a massive toll on her mental health, driving her to insanity. As all of this happened, Arnaud maintained the cover story about her abandonment, keeping her a secret from even her own family.

However, 25 years later, the flower picker who had an affair with Mathieu went on to have Alba reach out to Arnuad. Through emails, she revealed her abandoned kid’s identity and compelled the patriarch to include her in his will. Manon ended up stumbling across this information while going through her grandfather’s computer to search for her mother. Consequently, things began to slot into place. As a result, the young attorney decided to embark on a vengeful quest. She begins by sending out an interview invite to Alba, whom she later frames for her grandfather’s murder. When this attracts police attention, she turns it around on the rest of the Lasserre family and attempts to have the other woman killed to further incriminate them. Nonetheless, Manon’s scheme ends up being for naught when Alba continues to survive and fight back against her aggressor.

Does Alba Kill Manon? Is She Dead or Alive?

Initially, Manon manages to cement herself as an ally in Alba’s eyes by being the first one to reach out for help. Her defense attorney schtick works well, especially when the truth about her mother’s mistreatment comes out in the open. For the same reason, she escapes any suspicions for a long time. In fact, when Alba gets a hint about the mastermind’s identity, through a book left behind in Josephine’s ward room, she takes it as a sign that points toward Haiden rather than his sister. Consequently, she’s filled with righteous fury when she learns that her son, Leo, is currently hanging out with the same man whom she believes to be the killer. Naturally, Manon can’t allow it when the single mother storms out, armed with a gun and the intention to kill her brother.

Therefore, the circumstances force Manon to finally reveal her secrets and confess to her involvement in Arnaud’s murder. Nonetheless, she makes the confession at an opportune time when the duo is in a car together. As such, she’s able to manipulate them into a crash and attack Alba. Still, in time, both women manage to make it back to the estate. However, they seem to be too late, since young Leo has already killed Hadrien in attempted self-defense. Since he was the only real family Manon had left, she vowed to make Alba and her son pay for the death. The lawyer plans on confessing everything to the authorities. As such, Leo won’t be able to explain away Hadrien’s murder as self-defence since the latter was never dangerous to begin with.

As a result, Alba offers Manon a different deal to ensure her son’s safety. She promises to remain silent about the latter’s crimes and pin them all on Hadrien. Since he’s already dead, he won’t have to deal with the consequences of wearing the killer’s tag, and the lawyer can get away with her crimes and return to her regular life. Initially, the sister rebuffs this offer, insisting that her drive for her brother’s revenge is greater than her need for survival. Yet, things change when Alba pulls a gun on the other woman. Ever since she had Leo, the single mother has done everything in her power to protect him. Therefore, she’s prepared to commit a cold-blooded murder if it means her kid can be safe. It seems Manon is aware of the same, which is why she ends up agreeing to the single mother’s offer. In the end, the former survives and uses her brother’s death to cover up all her crimes.

Is Alba Really Arnaud’s Daughter? Who is Her Mother?

Alba’s biological connection to Arnuad is the crux of what gets her in trouble with the Lasserre family. Her inclusion in the patriarch’s will is the only valid reason the cops have to suspect her involvement in his murder from day one. Furthermore, it creates friction between her and Beatrice, since her share in the family’s wealth prevents the latter from selling the fields and the estate for a profit. Nevertheless, this foundational truth is eventually challenged when Alba decides to go on a quest to learn about her biological mother. Off the bat, she makes a safe assumption that Arnaud likely had her in an affair with one of the many flower pickers who worked in his fields.

Consequently, Alba searches through the family’s employment dossier to find someone who could be her mother. This brings her to one elusive employee, whose records seem to have all been torched. Yet, one piece of evidence remains: her photos with Mathieu, Arnaud’s son. The photographs make it evident that the two had a romantic relationship during his marriage to Josephine. As such, Alba confronts the man, hoping to learn convoluted truths about the family. However, she ends up learning something unexpected about herself. As it turns out, Arnaud is not her real biological father.

Instead, her mother, Nadia, was actually impregnated by Mathieu, who loved her dearly. Eventually, Josephine discovers their affair after finding Nadia while she is giving birth in the rose fields. Once the patriarch learned about the whole thing, he decided to take matters into his own hands. He kept the baby a secret from Mathieu and manipulated the mother into giving her child up. Afterward, he fed Josephine lies about his own involvement with the flower picker to save his son’s reputation. In the end, the truth comes out once Mathieu secretly takes a paternity test for Alba after noticing her similarities to Nadia.

Who Buys the Lasserre Estate?

In the end, once Alba and Manon come to an agreement, the former parts ways with the Lasserre family. She gets to keep Leo by her side, after Hadrien’s death is explained away as an instance of self-defence. From there, the single mother works on herself, finds a stable job, and even gets a humble apartment for herself and her son. Still, it seems she can’t escape her biological family forever. Even though Alba isn’t Arnaud’s daughter, she is still a partial Lasserre, thanks to Mattheiu. Therefore, while she isn’t inclined to the patriarch’s wealth, she gets an alert about the sale of the family estate. It seems that the buyer’s lawyer wants her present for the handover of ownership.

Consequently, Alba is around, as are the other surviving Lasserres, when the buyer makes her entrance. As it turns out, the buyer is none other than Nadia, the former flower picker who got caught up in Mathieu and his father’s games. After the woman left the estate, she went on to build a successful life for herself as a perfumer. Nonetheless, her past continued to haunt her, particularly due to her guilt about abandoning her daughter. For the same reason, she compelled Arnaud to include her in his will, which jump-started the entire fiasco. However, it seems Nadia has returned to the estate for better or for worse.

Does Beatrice Die? Who Attacked Her?

Toward the end of the season, Hadrien and Manon aren’t the only Lasserres who come close to their demises. Shortly after Beatrice discovers the truth about Josephine’s condition, she calls her granddaughter up, hoping that the recent revelations would compel her to help her get out of the clinic. Nonetheless, Manon already knew about her mother. Therefore, she uses her message to lure Alba to the clinic. While the specifics of her plan remain ambiguous, it’s likely that this is done to frame her for yet another murder.

As such, when Alba arrives on the scene, she is met with Beatrice’s dying body. It is possible that Manon has something to do with her grandmother’s attack. Nevertheless, the attack ultimately ends up being futile. Alba discovers Beatrice in the nick of time, allowing nurses to get the older woman to an ambulance before she runs out of time. In the end, Beatrice’s fight for her life becomes yet another gamble, one that she hallucinates inside her head. Fortunately, for her, the odds seem to be in her favor, and she survives the ordeal. Even so, after returning to the land of the living, her mind seems to have wiped all memories of her death, leaving the identity of her attacker a mystery.