The heroes must find a Heart Crystal on Rainbow Island. There, Onchao becomes jealous of his little sister because he wanted to play with his friend Flair alone. Onchao trots across the island alone and finds the Heart Crystal in the Rainbow Dome.

A nice plant around Panthea's former palace is poisoned and turns into the evil Night Vine that seals up the Palace, turning it into the Dark Castle. The Night Vine will take over Centopia, and corner Elves and Unicorns.