The teenager Mary "MK" Katherine returns to the house of her estranged father Professor Bomba, who is a widower scientist obsessed to find tiny creatures that he believes that would live in the forest. MK does not accept the lack of attention of her father with her and decides to leave him again. However the creatures do exist and protect the forest against the evil Boggans and their leader Mandrake that wish to destroy the forest. Near the solstice, Queen Tara chooses a pod to inherit her healing powers, protected by the Leaf-Men and their leader Ronin. However, they are surprised by an attack of Mandrake and the Boggans and Queen Tara is deadly wounded by Mandrake. Meanwhile, MK is leaving home and she looks for her three-leg dog Ozzy that has ran to the forest. She finds Queen Tara dying and she shrinks MK with her powers and gives the pod to her. Further Queen Tara asks MK to take the pod to Nim Galuu. When Ronin meets them, he decides to bring MK and the pod to Nim Galuu, with the protection of the young Leaf-Man Nod and the slugs Mub and Grub. Along the dangerous journey, they are chased by Mandrake that wants to bloom the pod in darkness to destroy the forest.