Summer Glau is best known for her roles in science fiction and fantasy television series; as River Tam in Firefly (2002) and its continuation film Serenity (2005), as Tess Doerner in The 4400 (2005–2007), as Cameron / Allison Young in Terminator: The Sarah Connor Chronicles (2008–2009), as Bennett Halverson in Dollhouse (2009–2010), as Skylar Adams in Alphas (2011–2012) and as Isabel Rochev / Ravager in Arrow (2013–2014).
Glau’s first television credit was a guest role as a ballerina on the 2002 episode “Waiting in the Wings” of the television series Angel. There she caught the eye of director Joss Whedon, who later cast her in his critically acclaimed but short-lived TV series Firefly as River Tam, a role she reprised for the show’s feature film sequel, Serenity.
Glau appeared on the episode “Love Conquers Al” of the TV series Cold Case. She had a small role in the film Sleepover, in which she played a high school senior named Shelly. She also appeared in the CSI: Crime Scene Investigation episode “What’s Eating Gilbert Grissom?”, and the second season of The Unit, portraying Crystal Burns, the girlfriend of Jeremy Erhart.
In 2006, Glau played Tess Doerner, a paranoid schizophrenic returnee in the second-season premiere of The 4400 (episode “Wake-Up Call”), and became a recurring character from season 3 onwards. She also starred in the horror comedy film Mammoth. Glau was cast in the ABC Family TV movie The Initiation of Sarah.
In Terminator: The Sarah Connor Chronicles, a series that debuted January 13, 2008, Glau played the role of Cameron Phillips, a Terminator infiltration unit sent back to protect John Connor and Sarah Connor from Skynet. The seventh episode of the series, “The Demon Hand”, included several scenes in which Glau (in character as Cameron) dances ballet and in the same series, Glau also played the human doppelganger of Cameron, Allison Young appearing in two episodes: “Allison from Palmdale” and “Born to Run”. Glau also guest starred as herself in the 2009 episode “The Terminator Decoupling” from the second season of the CBS situation comedy The Big Bang Theory.
Glau joined the cast of Joss Whedon’s Dollhouse in the early part of the show’s second season. She portrayed Bennett, the programmer for a rival Dollhouse. She later joined NBC’s The Cape in a leading role.
In June 2010, she was confirmed as the female lead in the horror comedy film Knights of Badaqssdom. In 2011, Glau was cast on Alphas as Skylar Adams, a recurring alpha and mother to Zoe Adams, and a former acquaintance of Dr. Rosen and Nina. Glau voiced Kara Zor-El in the DC Comics original animated movie Superman/Batman: Apocalypse.
Glad appeared as the recurring character Isabel Roche aka Ravager in the 2014 season of Arrow and in 2016, reunited with former Firefly co-star Nathan Fillion in an episode of Castle.