Worlds are colliding with “Supergirl’s” latest casting announcement: Laura Vandervoort, who played Supergirl on “Smallville,” will join the cast of the CBS drama in a recurring role.

Vandervoort will play Indigo, based on the DC Comics character. The “Supergirl” producers describe Indigo as a living, strong-willed supercomputer that was sentenced to Fort Rozz after turning against the people of Krypton. Now that she’s on Earth, nothing will stand in her way. Vandervoort will make her debut in episode 15 of the CBS drama.

Executive producer Andrew Kreisberg noted that an upcoming installment of the drama will be a particular treat for fans of every iteration of Supergirl: “There’s gonna be an episode coming up that’s gonna have Melissa, Laura and Helen Slater [star of the 1984 “Supergirl” movie] all in the same episode. We’ll have three generations of Supergirl,” he said, admitting that he loved the idea of “the next Supergirl, who’s still a little girl, out there watching this… we always consider ourselves the custodians of this leg of the journey, but these characters came before us and they’re gonna come after us, and we’re just the lucky ones who get to be at the wheel for this portion of the ride.”

In addition to Vandervoort, “The Young and the Restless” alum Jeff Branson has been cast in the recurring role of Master Jailer, the forceful and unrelenting jail guard on Fort Rozz who showed no mercy. Now on Earth, he is hellbent on catching all of the Fort Rozz escapees and brutally bringing them to justice. His first appearance will be in episode 14.

The casting announcements were made Monday during the Television Critics Association press tour’s set visit day, in which press members were welcomed to the set of “Supergirl” on the Warner Bros. Studios lot.

Though Vandervoort played the role of Kara/Supergirl on “Smallville,” that role is now, of course, played by Melissa Benoist on the CBS series.

Since her role on “Smallville,” Vandervoort has starred on Syfy’s “Bitten,” which recently announced that Season 3 would be its last — freeing the actress’ schedule for her “Super” return.