When Emily Prentiss's mother Elizabeth announce that she's getting married again, 15 years after her divorce from Emily's father, no one is happier than Emily. When she meets the daughter of her mother's fiance, Jennifer Jareau, there's an instant attraction from Emily's side but Jennifer is engaged to Nathan. As the two women slowly get to know each other they gradually grow closer and eventually it develops into something more. Something that's stronger than either of them but it also causes a complete chaos. How will they handle their strong feelings for each other when there's so much at stake and other people is involved?