1 Book Found

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"I’m looking for a middle-grade or early YA novel (around 200–250 pages) that I read around 2018 in 5th grade. It was set in the modern day and followed a teenage girl as the main narrator, with a teenage boy as the other main character. The boy had a hereditary condition that remained dormant until his teen years, causing him to unknowingly transform into a feral wolf-man during full moons. At first, nobody knew what was happening—not even the characters, who didn’t seem to know what a werewolf was—so the story played out like a mystery. The boy would black out and wake up naked in random fields with no memory of the transformations, while the town blamed livestock killings on ordinary wolves. Eventually, they discovered the transformations were tied to the full moon. The creature could move on both four legs and two, and silver bullets were believed to be the only way to kill it. There was also a crazy old man who secretly researched and hunted supernatural creatures; he had an underground bunker with a reinforced metal cell where the boy was initially forced to stay during full moons. After escaping once through the sewers while transformed and causing destruction, the boy voluntarily agreed to lock himself in the cell every full moon. There was also a subplot involving an abusive father who returned while the family was gathered, and a strong adult man (possibly a relative or family friend) ultimately shot him with a shotgun. The book appeared to be a standalone and, from what I remember, wasn’t marketed as a werewolf novel because the characters treated the creature as something unknown rather than calling it a werewolf. I vividly remember the abusive dad trying ti get in during a hurricane party when everyone was gathered (they called it hurricane party by word)"