After her boyfriend Casey Jones is unable to get to Boston, Jane takes Maura to her dreaded high school reunion. She hates most of the people there but one former classmate that she liked, Steve Sanner, says he would like to discuss something with her. Before he can do so however, Steve is shot and killed while taking a walk on the football field. The killer used a steel wool-filled water bottle as a silencer. He worked for another high school classmate, Rory Graham, who says he wasn't having any trouble at the office or with co-workers. Based on his phone records, they suspect he may have been having an affair with another former classmate, Debbie Tibbet, but when she is found dead her husband tells the police she had recently become very secretive. A third dead classmate gives them the clue they need to identify the killer. Meanwhile Vince Korsak's ex-wife is back in town wanting money for a new enterprise. Vince would like to see his 16 year-old son Josh.

Jane and Maura investigate the stabbing death of Denise Ryan, who stumbled onto the stage at her daughter Dakota's dance competition with a pair of scissors in her chest. According to the dance studio owner, Coach JJ, Denise wasn't like the other moms and didn't get to know her very well even though Dakota has been going there for two years. The husband is eliminated as a suspect but the police responded to a disturbance at the dance studio two weeks ago when two of the other moms, Yvonne and Kim, got into an argument. When they learn that Denise had no credit history whatsoever, they realize that the plastic surgery she underwent was likely to hide her true identity. Korsak meanwhile has been avoiding his ex-wife Melody who wants him to co-sign a lease so she can open her yoga studio. He learns that his stepson Josh has been arrested for shooting a policeman with his own gun. Joss is angry and refuses to speak to anyone.