Lili Bumblebee lives alone in her house by the sea, in the middle of an ungodly mess. Just to get to her kitchen, she has to climb an actual mountain—but not the kind with alpine flowers and fresh air. But though she dreams of adventure, and none of the belongings she's accumulated over the years satisfy her, she'd rather stay home than brave the outside world that scares her so.
One morning, at her window as usual, she spies a funny-looking pile of odds and ends. And atop it, a baton waving out an S.O.S.! That does the trick. Armed with a sturdy protective umbrella (old habits die hard), Lili sets out into the dark maze of her cavernous home…