Yoohoo and his friends have gone to play in the ocean. They meet a squid and learn there is a black spring inside the ocean. Oops and Koops overhear this and tells Big Boss about the black spring. Big Boss orders them to search for the black spring since it may be where the oil spring lies. Oops and Koops find the ocean's black spring and unplugs the entrance.

Yoohoo and his friends go to Big Boss's castle to look for Pammee. On their way there, they pass the Death Forest and are affected by the scent of a mushroom that makes the mind go fuzzy. Not having control, they fall into a hole in the ground and are chased by a monster spider. They somehow overcome all the obstacles and find their way to the castle to save Pammee!