When their older brother and sister move out, Bastián Silvano has one job: protect the secret world they've all shared since they were children. For years, the world under the lake has been not just a landscape of underwater trees, mythical alebrijes, and paint and paper coming to life, it's been a safe space for their neurodivergent brains. But when Lore Garcia finds their way in, everything changes. The world under the lake pulls Bastián and Lore in without warning, and makes Lore's own neurodivergence part of its landscape. The once-unshakable bond between the Silvano siblings fractures-their brother thinks Lore will be the ruin of their world, while their sister thinks there's more to the lake's magic than any of them know. And the mistakes Bastián will do anything not to repeat, and Lore will do anything to hide, find their way above and below the surface.As Bastián tries to hold both of their worlds together, Lore must decide how much they'll risk for the magic they're now part of, and for Bastián.