A bonus scene at the end of The Expanse season 6 episode 4 ("Redoubt") confirms Jules Pierre-Mao's fate despite the revelation's absence from the books. Introduced in season 1 as the owner of Mao-Kwikowski Mercantile and its subsidiary Protogen, François Chau's Jules Pierre-Mao authorized unethical research on the alien substance known as the protomolecule, including an experiment that killed his daughter Julie and wiped out the population of the asteroid Eros. Mao featured as The Expanse's principal villain from the series' beginning through the first half of season 3, when he was handed a life sentence in prison for his crimes. The Expanse season 6 reveal's Mao's off-screen death by way of his elder daughter Clarissa, who has taken a different path from her father.
Clarissa's complicated journey began in season 3 when she aggressively pursued vengeance upon James Holden for imprisoning Jules-Pierre Mao. She had long felt undervalued by her father and her feelings of inadequacy characterized their complicated relationship. Stopping Klaes Ashford from destroying the ring station and annihilating humanity aboard the Behemoth didn't spare Clarissa of a life sentence due to committing multiple murders. In The Expanse season 5, Clarissa returned to the fold, escaping from prison with Amos in the aftermath of Marco Inaros' asteroid attack on Earth. Clarissa's subsequent revenge arc has seen her join the crew of the Rocinante as a mechanic and begin to mend her rapport with Holden and Naomi.
In episode 4’s bonus scene titled "Night Watch," Clarissa learns from a newsfeed that Jules-Pierre Mao has died in prison due to an underlying medical condition. In the ensuing moments, she breaks down in a fit of tears and rage. The scene accomplishes what the books didn’t by revealing Mao’s fate and by unearthing Clarissa’s lingering attachment to her estranged father in light of her character transformation over the course of The Expanse.
In The Expanse book series, written by James S.A. Corey, Jules-Pierre Mao's fate following his prison sentence never surfaces. Leaving the character's definitive unknown doesn't necessarily create a problem, as it's equally satisfying to observe Mao relinquish his power and disappear into irrelevance after wreaking so much havoc on the universe. On the other hand, by acknowledging his death, the Prime Video series provides some closure to its earlier plotline when the protomolecule emerged as an alien threat to all human life.
More importantly, the manner in which the news impacts Clarissa provides a deeper look into her character. At this point in The Expanse season 6, it might be reasonable to assume that Clarissa has left her old self behind, especially the part of her that adored her disreputable father. However, this additional scene clarifies that the parent-child relationship still painfully resonates with her. After her initial outburst, Clarissa records an entry in her private journal, trying to make sense of her anguish and at one point declaring, "I wish you loved me," followed by, "I wish I hadn't loved you." The short sequence gives Clarissa a moment of solitary reflection that she hasn't been afforded since her revenge arc began.
Clarissa has evidently evolved from her spiteful ways, but this scene serves as a reminder of her toxic upbringing that led her on that path in the first place. Clarissa's inability to separate herself from her past constitutes a profoundly authentic portrayal of trauma and guilt. Physically harmed from her implanted mods beginning to degenerate her body and emotionally scarred from her troubled backstory, Clarissa sees her inner turmoil amplified more than ever before in The Expanse season 6.
The Expanse releases new episodes Fridays on Prime Video.