WARNING: The following contains major spoilers for The Expanse Season 5, Episode 6, "Tribes," available now on Amazon Prime Video.
Clarissa Mao was once fueled by revenge, aiming to kill Holden for his role in taking down her father, Jules-Pierre Mao. However, following the events on the Behemoth in Season 3 of The Expanse, she had a change of heart and gave herself up for multiple counts of murder and the destruction of the UNN Seung Un. Due to her implants, she was placed in a high security prison known as The Pit, where enhanced criminals are kept. In Season 5, Episode 6, "Tribes," Clarissa finally shows why The Pit was the right place for her, by using the enhanced speed, agility and strength provided by her implants to beat seven shades out of a man, before killing him with his own rifle.
The moment in question comes as Clarissa and Amos, who had been visiting her in The Pit when one of Marco's asteroids hit nearby, find themselves in need of supplies after making their way from the destroyed prison. After leaving The Pit, they happen upon a dead body with no visible cause of death, and Amos proceeds to loot the corpse. Shortly afterward, they meet another man who has set up camp. The man compliments Clarissa on her newly acquired coat and offers them a drink from his canteen. This gives Amos reason to suspect the man, so he gets the duo moving again without delay.
Prior to leaving, the stranger warns them of another survivor who is controlling a fenced-off area to the south. Amos then explains the new normal they find themselves in to Clarissa, stating, "the funny thing about civilization is that it keeps you civil. Get rid of one, you can't count on the other." Once he is certain that the old man isn't following them, he changes their path so they'll come directly into contact with the survivor to the south.
Throughout all this, Clarissa's system has been working through the last of the enhancement blockers that the prison injected her with, which cause sickness and muscle cramping. Amos recognizes Clarissa is suffering and they will need supplies soon, so an encounter with the armed survivor is their best option. When they arrive, the man is suspicious of them, telling Amos to strip to make sure he isn't armed. Once he's satisfied, he explains he's going to kill Amos, causing the hidden Clarissa to activate her augmentations and take the man down in spectacular fashion, spraying a surprised Amos with the man's blood before she passes out from the strain.
With the man's cabin now available to them, Amos takes Clarissa inside to recover. Once she awakens, she tells Amos about a poem she wrote while in prison: "I have killed but I am not a killer because a killer is a monster and monsters aren't afraid." This leads her to question Amos' motives. She asks why they went out of their way to confront a man they knew was hostile. Amos responds that they needed supplies and the man had them, making Clarissa uneasy.
Amos was evidently unafraid of the danger posed by the armed man, and ultimately felt no remorse over his death. Clarissa, despite being the one who killed the man, becomes the voice of morality. This causes Amos to realize he's been away from his crew on the Rocinante for too long, as he acknowledges Holden wouldn't have approved of his actions, something that usually keeps Amos in check. By saving Amos' life the way she did, Clarissa certainly proved how dangerous she can be, but Amos away from his crew for a prolonged period may prove to be more dangerous.
An adaptation of the novel series of the same name by James S.A. Corey, The Expanse stars Steven Strait, Cas Anvar, Dominique Tipper, Wes Chatham, Shohreh Aghdashloo and Frankie Adams. New episodes of Season 5 premiere Wednesdays on Amazon Prime Video.