Young Mae lost her mother in a tragic accident a few years back, although mother's body was never recovered from the raging river into which their car crashed. Mae is devastated because her father, now that enough time has elapsed for proof of death, must sell off his wife's farm, along with her wild stallion Percy, who seems dangerous to anyone who comes near him. However, when Mae realizes that Percy is really a unicorn with amazing powers, she teams with a group of her young friends to save the creature from an age old billionaire who sustains his life through unicorn blood -- and who is now determined to get Percy in his clutches. But unless Mae can find Percy's missing unicorn horn, and restore the full extent of his magical powers, it appears that he is doomed -- unless Mae can pull off a last-minute miracle to save Percy from a terrible fate...