Loud music wakes Vincent up in the middle of the night, and he sees a red pickup truck pull in at the house across the street. A red-headed girl and a man decked out in a sparkly western shirt and cowboy hat get out, and he proceeds to two-step up and down the driveway before they go inside. Through the windows, Vincent can see them dancing in unison, the man downstairs and the girl upstairs. Their movements are virtually identical and they begin spinning faster and faster. Suddenly, he sees what looks like horns begin to sprout from the man's head! It seems there's another monster mystery begging to be solved! The next day at the library, Vincent reads about a border urban legend involving a handsome stranger who is really a dancing devil! He also meets a new student, Lilith del Diablo, who he saw the night before! Soon Vincent and his friends have gained Lily's trust and she tells them her biological father, Luciano del Diablo, is intent on forcing her to become his partner in crime terrorizing girls at dance halls along the US-Mexico border. Meanwhile, Vincent finds his mother's trunk in the garage and is shocked to find it's full of monster-fighting tools--silver coins, a slingshot, wooden stakes--and a journal with information on the various beasts. Why would she have this information? Does he come from a long line of ancestors who fight unnatural demons? Is that why evil creatures are constantly moving in across the street?! With help from his mother's diary, Vincent concocts a plan to save Lily from the dancing devil, but it's going to take all his friends' and cousins' wits to make it work. This bilingual book for intermediate readers, the fifth installment in Garza's Monster Fighter Mystery series, follows the dangerous battle between a seasoned devil and one unsure of her powers, a witch owl and several very determined kids!