The hurricane-swept town of St. Augustine is the only home Lucely Luna has ever known. It's the same home her father grew up in, and his parents before him. In fact, all of the deceased relatives in the Luna family now live as firefly spirits in the weeping willow tree in their backyard.

Shortly before Halloween, a mysterious storm appears on the radar heading towards St. Augustine, causing Lucely's firefly spirits to lose their connection to this world. In an effort to save them, Lucely finds a spell to bring them back to life, but accidentally brings more spirits to the town than she'd planned. Ghosts start showing up all around town, some more dangerous than others, wreaking havoc.

Lucely will have to band together with her best friend and occult buff, Syd, along with Syd's witch grandmother, Babette, and her tubby tabby, Chunk, to fight the haunting head on, save the town, and save her firefly spirits all before the full moon culminates on Halloween.