In "Solitude," an upcoming episode of "Supergirl," there are two Supergirls in town -- in spirit, at least. "Bitten" star Laura Vandervoort, who played Kara Zor-El on "Smallville," guest stars in the episode as Indigo, "a living, strong-willed supercomputer that was sentenced to Fort Rozz after turning against the people of Krypton."

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"Solitude" -- Kara travels to Superman's Fortress of Solitude in hopes of learning how to defeat Indigo (Laura Vandervoort), a dangerous being who can transport via the Internet and who has a connection to Kara's past. Also, James's relationship with Lucy reaches a crossroads, on SUPERGIRL, Monday, Feb. 29 (8:00-9:00 PM, ET/PT) on the CBS Television Network.

"Supergirl" airs Mondays at 8 pm EST on CBS. Developed by producers Greg Berlanti, Ali Adler and Andrew Kreisberg, the series stars Melissa Benoist, Calista Flockhart, David Harewood and Chyler Leigh.