Meet the Fluffles, four rabbits from Snowberry Glade. When their peaceful picnic suddenly gets interrupted by a baffling event, the curious rabbits have no choice but to dive into the unknown underworld beneath their garden.
A mysterious call for help pulls them deeper into a realm of endless tunnels, puzzling doorways, cryptic clues and mind-blowing technology. They soon realise that this dark but magical world is in trouble and they need to help.
But when their youngest brother Binky falls seriously ill, navigating the tunnels to find the way out becomes a desperate race against time. The only one who can save them is the Great (but slightly confused) King Moldrian...