Onyango gets lost while playing with four friends in a forest on the outskirts of Nairobi. The forest is home for Chakaa-Chaka-Chaka, a hairly giant whose favourite meal is children. After getting advice from the only person who has ever survived an encounter with the giant, the four friends set of on a thrilling adventure - OSO! Operation Save Onyango! The children face obstacle after obsatcle from crocodiles to hyenas and other screaming and splashing creatures on their way to the giant's cave. Will they be on time to save Onyango? How will they face the giant? Will they survive?