Based on the popular novel for young adults by Frank Sacks, this heart-warming drama concerns Billy Hastings, an 11-year-old boy whose life is shattered after his leg is permanently damaged by a drunk driver. Billy and his mother Julie move to a new town in hopes of escaping the bad memories of the accident. Not long after they arrive, they visit a threadbare circus, where they discover a neglected horse. Feeling sorry for the animal, they arrange to take it home, only to discover that the horse is pregnant. That's the least of their surprises, though; the horse shortly gives birth to a unicorn, which appears to have magical powers.