River Tam

River Tam is one of the main characters from the short-lived television series Firefly, as well as its sequal-in-movie-form Serenity. In canon, she is the younger sister of Simon Tam, on the run from the Union of Allied Planets after being held prisoner by a secret government-run facility intent on turning her into a psychic weapon. The experiments ended up permenantly damaging her brain, leaving her mentally scarred and highly unstable. Rescued by her brother at great cost, the siblings found themselves on the transport ship Serenity and were taken in, the crew becoming something of an extended family. Taken from after the end of Serenity, River is starting to recover thanks to her brother's efforts and the support and trust of the crew, but is still "a little whimsical in the brainpan".

In Bete Noire she remains in her brother's care, though she's starting to push outward, befriending several of the city's inhabitants and securing a job as Tony Stark's personal assistant.