When the world is overtaken by monster alien plants that emit toxic pollen and swallow up people, three kids on a remote island look for clues in their unusual allergies to understand their immunity to the invaders.

A sequel to Bloom finds Seth, Anaya and Petra locked away in a government lab with other immune kids while the outside world is overrun by an alien infestation of giant insects that spread disease, undermine building foundations and carry off human victims.

Hoping to adopt a pet to find a sense of belonging in her busy family, Maggie is disappointed to discover she is severely allergic to anything with fur and tries to find a pet to love anyway.