Billy, Nicola and Mr Gopal are off to India in a flying boat to solve a baffling mystery! The gum that comes from the wonderful bubblegum trees that grow in the Indian jungle has not been delivered for two months. Without this secret ingredient, there'll be no more Gopal's Best Pink Bubblegum, and even more importantly, no more Bubblegummies - the people who live in the trees and harvest the gum. It's not an easy mystery to solve - and soon the friends are involved in a bungee-jumping, tiger-trouncing, woodcutter-walloping, bubblegum-blowing adventure!