The body found in a National Park turns out to be the daughter of the wealthy McNamara family and may be the victim of the Ghost Killer.
The final member of the McNamara family, Stephanie, who Hodgins grew up with is killed. The FBI offers Booth al the resources he needs to solve the case.
The last McNamara was not killed because the gardner was the illegitimate daughter of the patriarch.
Angela links Stephanie McNamara to all the murders. She was the ghost killer, but someone killed her.
Stephanie started killing at age 15, and the teacher convicted of the original murder took out Stephanie and others. Case solved.