Summer Glau

 Glau's debut television role was as a guest ballerina in a 2002 episode of the television show Angel. Director Joss Whedon saw her and decided to cast her as River Tam on his short-lived TV series Firefly. She also played in the role for the sequel Serenity. Glau had earlier applied for the Power Ranger (White Wild Force Ranger Alyssa Erile) part in Power Rangers Wild Force, however, she was beaten by Jessica Rey. Glau had a small part in the movie Sleepover, in which she played high school senior Shelly. She also appeared on CSI: Crime Scene Investigation episode, "What's Eating Gilbert Grissom?" ", and season 2 of The Unit as Crystal Burns (the girlfriend of Jeremy Erhart). Glau was the paranoid schizophrenia returnee Tess Doerner in season 2 of The 4400. She became a regular character in season 3 and beyond. Glau also appeared in the film of the same name, a horror comedy called Mammoth. Glau appeared in The Initiation of Sarah, an ABC Family TV film. Glau played Cameron Phillips, a Terminator-infiltration unit returned to Skynet in order to safeguard John Connor (and Sarah Connor). The seventh episode of the series, "The Demon Hand" was a scene that featured Glau in character as Cameron, dances in ballet. In the second season's episodes "Allison From Palmdale" (season 2), Glau played Allison Young the human doppelganger of Cameron. Glau also guest starred as herself in an episode in 2009 of the CBS comedy series The Big Bang Theory