CBS is drawing from the DC Comics superhero TV and film universe for the latest additions to its Supergirl pilot. Dean Cain, who played Clark Kent/Superman in the 1990s TV series Lois & Clark: The New Adventures Of Superman, and Helen Slater, who played Kara Zor-El/Supergirl in the 1984 film Supergirl, are set to guest star in what is described only as “mystery roles.”

Based on the DC Comics characters, Supergirl — from Warner Bros. TV and Berlanti Prods. — centers on Kara Zor-El (Melissa Benoist). Since arriving on Earth, the Krypton-born Kara has been hiding the powers she shares with her famous cousin, Superman. But now at age 24, she decides to embrace her superhuman abilities and be the hero she always was meant to be. They join previously announced Benoist, Chyler Leigh, Calista Flockhart, and David Harewood.