Castle and Beckett discover evidence that links a young woman's murder to Sen. William H. Bracken (Jack Coleman) -- the man responsible for the murder of Beckett's mother; Beckett faces complications as she tries to finally bring Bracken to justice.
When three children disappear while riding their bikes on the same path as a similar unsolved disappearance 30 years ago, the BAU team comes in to investigate.
Several of the doctors compete to be the new face of Seattle Grace; April brings an emergency case to the hospital; Alex and Jackson work with a transgender teen couple; new policies test the patience of the staff.
Ziva is forced to dig up a buried chapter of her life when a Marine's body surfaces halfway around the world.
Twelve years into the future, T'Pol reveals that she and Archer are living in a colony of the last surviving humans.