All Quinn Mannerling wants to do is lead a normal life. He can, as long as there's no full moon.
Leine Mannerling swapped babies at the hospital where she worked, giving her government agent brother and his wife the baby of a woman who just died, and taking the one they had. According to her sister-in-law, the first born of every generation up to the tenth would be a werewolf, and that's what she gave birth to.
Leine stole her dying boss' winning lottery ticket, quit her job and moved around a lot over the years, to keep Quinn safe. But Candice, her dead boss' wife, hired a detective to find Leine. The relatives of the dead woman are looking for their nephew, and Quinn has feelings for Diane Steele, the next door neighbor's daughter.
Quinn accidentally kills the relatives of the dead woman when they thought he was their nephew. He buries them far away, but drunken hunters, along with the Reverend, burst into Leine's home while she was arguing with Candice. Quinn changes, and the Reverend and Candy are killed. James Howard, the detective Candy hired to find Leine, is charged with the murders. He escapes, and holds Diane, Quinn and Leine hostages in the basement until they come clean about who really killed those people.