Something strange is going on by the slimy river Oozeburn. But Jin is the only one who knows. The ancient predator Zilombo is loose and has snatched Jin's baby brother. When Mizz Z, a secret agent, arrives to investigate, the race is on to save him. But the beast's mysterious powers are evolving. She's getting stronger. As Jin, his sister Frankie and Mizz Z make their plans, Zilombo grows hungrier...