Ella and Felix are called out on a mission to a peculiar land, surrounded by precipitous mountainsides. Its inhabitants live in houses attached to the rock and the only way of getting around is by goat worm. The super slime used to attach the houses to the mountainsides lasts for a year before it goes into release mode, then it must be re-attached. The trouble is that the super slime is found in the umbrella flowers that grows on the umbrella tree, that only blossoms once a year. And now the worst thing imaginable has happened: the umbrella snapper has built a nest in the umbrella tree, right as it’s blossoming. Will Ella and Felix manage to solve this mess? And could the solution lie in the odd hats that all the people wear on their head, that looks a lot like paper planes?