To prevent Linda Danvers from finding the essence of the Earth Angel that made up Supergirl, a mysterious being has tricked guest-star Mary Marvel into believing that Linda is actually a demonic impersonator who must be stopped at all costs! Meanwhile, in Leesburg, the Bizarro Supergirl goes head-to- head with Comet, who's trying desperately to rein her in!
— Description from Comic Vine community (comicvine.gamespot.com).
