Catherine leads the investigation of various instances of a Peeping Tom as the team rush to catch the Tom before his crimes escalate to assaults -- a path which, though unusual, is suggested by specific evidence found at the crime scenes. Meanwhile, Sara reopens a case involving her friend, a district attorney, who was shot during an attack on her husband three years prior. As Sara digs back into the case, the district attorney goes into potentially lethal surgery to remove the bullet.