Red Kryptonite causes Clark and Superman to be split into two separate beings, but Superman tries to take steps to prevent them from being reunited when the effect wears off.
Supergirl [Linda Danvers]; Comet the Super-Horse [also as Biron] (as Biron in flashback, origin); Fred Danvers; Edna Danvers; Mace Greede; Matt Carver; Super-Cat [Streaky] (cameo); Krypto (cameo); Superman (cameo); Maldor (flashback); Circe (flashback)
Synopsis
Comet telepathically tells Supergirl how he was originally human, and loved by the sorceress Circe, until a jealous rival caused him to be changed into a horse.