Tummi builds what he thinks is a bee-caller, but it instead attracts beevilweevils, insects that devour the Gummiberry bushes. Tummi and Gusto then go on a dangerous mission to locate a replacement Gummiberry sapling. When Gruffi, Zummi and Grammi go on a rescue mission to find Tummi and Gusto, they encounter talking trees who want revenge for the Gummis deserting them during the Great Gummi Exodus.