Summer Glau has been a ballerina from the time she was a small child. While it would be her acting career that would bring her face to face with her largest audience, it was her background as a dancer that would provide her with the chance to do so. After appearing in a few commercials, she appeared on the Joss Whedon series Angel as a ballerina in the episode Waiting in the Wings. Whedon was so impressed with the young actress' debut performance that in 2002, he cast the then-21-year-old in the challenging role of River in his new series Firefly. Despite immediately earning a hardcore cult fan base, Firefly's ratings would prove to be unsatisfactory for Fox, which pulled the plug after only 11 episodes. Glau had made her mark, however, playing a traumatized prodigy running from the interplanetary authorities aboard a cargo ship. She went on to test her acting chops by appearing on shows like CSI and The 4400, before reprising the role of River for 2005's feature film adaptation of Firefly, Serenity. In 2006 she signed on to star alongside Tom Skerritt for the TV movie Mammoth. She was a regular on several short-lived TV series - Terminator: The Sarah Conner Chronicles starting in 2008, and in 2011 she joined the cast of the drama series The Cape. Glau since has made a career out of guest-starring and recurring gigs on genre shows like The Big Bang Theory, Whedon's Dollhouse, Chuck, Alphas and Arrow.