• Five Midnights by Ann Dávila Cardinal, Tor Teen, 288 pages. $17.99.

American horror fiction tends to be conservative in its settings, with small heartland towns a perennial favorite. As for its protagonists, they tend to be white. Even the recent film The Curse of La Llorona, with its boogeywoman based on Mexican legend, depicts her tormenting a Californian Anglo family with her deadly lamentations.

Ann Dávila Cardinal, the director of recruitment at the Vermont College of Fine Arts in Montpelier, breaks those patterns with her refreshing young-adult novel Five Midnights. Set in urban Puerto Rico, it's a twist on the pan-Latin American legend of El Cuco, a shape-shifting monster that parents use to threaten unruly kids.

While the legend may seem simple — El Cuco punishes bad young 'uns — the monster's lack of a fixed form invites metaphorical interpretations. In Five Midnights, the victims are teenage drug users and dealers who share a childhood bond; over the book's time frame of less than a week, they begin perishing under mysterious circumstances, each at midnight on his 18th birthday.

Even before the young men's deaths, their fates point to broader social ills, leading a barrio priest to theorize about the significance of the El Cuco mythos. "I think it's no accident that it's coming up again now when the island is in such terrible shape," he says. "Legends like El Cuco reassure people that there are still consequences, that the laws of right and wrong are still upheld."

Following that lead, Dávila Cardinal uses El Cuco to explore a community's hopelessness and anger at economic exploitation by the mainland U.S. One of her two protagonists, Lupe Dávila, runs straight into that anger when she arrives from her home in Vermont to spend summer on the island with her uncle, the local police chief.

Like the author, Lupe is a self-described "Gringa-Rican," but to the locals she meets, she's just a gringa. It doesn't help that she comes sporting major attitude and an eagerness to play detective. "Why not skip on off in your combat boots and run to Starbucks or something," the sister of the first victim says scathingly after Lupe attempts to crash the memorial.

Only Javier, the novel's second protagonist, is willing to give Lupe a chance. An addict in recovery, he wants to save his childhood friends from the fate that appears to loom over them all. But can he save himself?

Writing short chapters from various close-third-person points of view, Dávila Cardinal gives substance to characters who might otherwise have been stereotypes. Marisol, the aforementioned grieving sister who derides Lupe as a "blanquita," isn't just a mean girl. We learn that her anger is grounded in years of watching as mainland investors buy up pieces of her neighborhood.

While Five Midnights doesn't shy away from negative aspects of its setting — warehouse drug dens, demolished homes soon to become fast-food joints — it doesn't portray Puerto Rico as a wasteland, either. In search of the murderer — or the monster — Javier and Lupe crisscross a range of towns and neighborhoods whose vibrancy Dávila Cardinal evokes in loving prose: "[t]he rich textures of the broken concrete buildings, the colors of the houses washed on in waves of patina..." And her mouthwatering descriptions of pastelón, bacalaítos and more will give readers a serious appetite for Puerto Rican street food and home cooking.

While Five Midnights has a body count, it's ultimately less of a terrorizing horror read than a coming-of-age adventure combining dark themes with fast-paced action. Javier fights a compelling battle to stay sober as he confronts his past, while Lupe learns some lessons about her heritage without losing her general kick-assness.

And the author has a sense of humor. At one point, facing an adversary who tells her she "should have stayed in Canada where you belong," our heroine fires off an action-movie-style quip that locals will appreciate: "I'm from Vermont, bitch."