Heather Taffet aka "The Gravedigger" (Deirdre Lovejoy) faces her final appeal before being sentenced to death. When she is killed by a professional sniper, the team investigates the identity of the shooter, leaving both Booth and Brennan's father, Max as possible suspects. Sweets deals with the aftermath of the shooting as he was very close by when she was killed, and also what Taffet said to him earlier about being a "weak link". Booth eventually discovers the shooter is Jacob Broadsky (Arnold Vosloo), a professional sniper and mentor that he once knew.