I hope you want more super-horse action because this issue is chock-full of it!
This issue begins with Linda/Kara and her foster parents still on vacation at the Supergirl dude ranch. Kara is still infatuated with her new pal ‘Comet’ the super-horse. She helps Comet pass as a mundane horse by using her super-powers to shoe and ‘brand’ him. Afterward Kara and Comet go on a ride where Comet finally communicates with Kara.
Comet telepathically speaks to Kara and tells her that he made her dream of him so they could meet. Comet is actually Biron, a centaur born in ancient Greece. Biron saved the life of a sorceress named Circe by warning her a evil sorcerer was trying to poison her. Circe concocted a potion that would turn Biron into a human but the cheesed-off sorcerer swapped potions with one that turned him into a horse. Circe tried to help out Biron by giving him super-powers. Maldor, the sorcerer, was still pretty cheesed so he performed a spell that sent Biron deep into space where he remained until young Kara’s spaceship accidentally freed him.
After arriving on Earth Biron kept an eye on Kara (creepy) hoping that they one day could fight evil together. He finally contacted her because he sensed an upcoming alien invasion. Biron and Kara then perform in a rodeo and then fight off the alien invasion.
Comet Biron and Kara do so well in the rodeo that the dude ranch manager sells him to a Hollywood studio.
On my patented Supergirl Wink © scale this issue gets: