Los Angeles narcotics detective John Kimble has long been after drug kingpin Cullen Crisp, who is a psychopath. After John arrests Cullen for a young man's murder, John is told that Cullen's ex-wife Rachel -- whose testimony could be a key to putting Cullen away -- is living in Astoria, Oregon, and that she has a son. John and his partner Phoebe O'Hara are sent to Astoria to find Rachel. Phoebe, a former school teacher, is assigned to go undercover as a kindergarten teacher at Astoria Elementary School, where Rachel's son is believed to be one of the students. The problem for John and Phoebe is the fact that they don't know what Rachel and her son look like. When Phoebe becomes sick before the undercover assignment is to begin, John must take her place, despite the initial misgivings of Principal Schlowski, who eventually befriends John. On his first day, John meets first grade teacher Joyce Palmeri, whose son Dominic is one of John's students. As John spends months on this assignment, he bonds with his students and introduces them to his pet ferret. The town's single mothers find themselves falling for John.