When a petrified human body is found buried in a mound of salt in a city de-icing truck, Booth and Brennan are on the case. They discover the victim, Ashley, was a 16-year-old high school volleyball player who had been missing for three weeks. When the team discovers Ashley was pregnant at the time of her death, they are shocked to find that nearly half of her volleyball team is either pregnant or already has a baby, and the press reports an alleged "pregnancy pact." Booth and Brennan must delve through the complex web of relationships to find a motive for Ashley's murder. Meanwhile, when Angela and Roxie discuss adopting a dog, they must confront larger issues in their relationship.