The lives of two CSIs are put in danger when an old enemy of Horatio's returns. When a truck full of confiscated weapons is hijacked and the weapons are released back into the public, Horatio links the crime to Clavo Cruz, a man he put away for murder years ago. However, on the day of Clavo's arraignment, a confiscated missile is launched into the courthouse to aid his escape, with Alexx inside. Meanwhile, Calleigh and Ryan investigates when an eleven-year-old boy is shot by one of the stolen weapons. The episode ends with the shocking revelation that Delko has been shot in the head.

The parents of a babysitter are murdered on the property where she is taking care of a 12-year-old boy in an upscale neighborhood. The investigation reveals the boy's parents were drugged at a nearby party and that there is a thief in the neighborhood who may be connected to the crimes. Also, Horatio investigates a doctor's shady past that includes lots of dead patients. Loosely inspired by When a Stranger Calls and Harold Shipman murders