For most kids, catching fireflies is a fun summer activity. For twelve-year-old Serwa Boateng, it’s a matter of life and death.

That’s because Serwa knows that some fireflies are really adze, shapeshifting vampires from the forests of Southeastern Ghana. Adze prey on the blood of innocents, possessing their minds and turning them into hulking monsters, and for generations, slayers like Serwa and her parents have protected an unknowing public from their threats.

Serwa is the best adze slayer her age, and she knew how to use a crossbow before she could even ride a bike. But when an obayifo (witch) destroys her childhood home while searching for a drum, do Serwa’s parents take her with them on their quest to defeat her? No. Instead, they dump Serwa with her hippie aunt and cryptic-obsessed cousin in the middle of Nowheresville, Maryland “for her own safety.” Now, instead of crossbows and battle armor, she’s dealing with mean girls and algebra, and for the first time in her life she doesn’t have to carry a staff everywhere she goes, which is . . . kind of nice, actually.

Just as Serwa starts to get the hang of this whole normal girl who doesn’t punch vampires every day thing, an adze infiltrates her school. It’s up to her to whip some of her classmates into monster-fighting shape before all of them become firefly food. And when she uncovers a secret that upends everything she thought she knew about her family’s role in the slayer vs. adze war, Serwa will have to decide which side of herself–normal girl or slayer–is the right one.

After all, seventh grade is hard enough without adding vampires to the mix.