A homicide on the Brooklyn Bridge leads Mac and Jo all the way to San Francisco to find a missing teenage girl, but they are not sure if she is dead or alive.
CSI searches for the shooter at a political rally, and the gun that he discarded in an alley afterwards is used in the accidental shooting death of a young girl.
The team connects the murder of a high schooler to a classmate who was dealing his prescription meds, and Lindsey returns home to take care of some unfinished business.
CSI tries to figure out who killed one of the owners of a modern-day speakeasy, and Adam tries to get through unresolved issues while taking care of his sick father.
Two people are shot and killed with a gun that was printed from a computer, and Jo tries to uncover the identity of an anonymous philanthropist who is giving away millions of dollars to random New Yorkers.
The team tries to figure out who killed a pick-pocket who fell from a building balcony onto a car, and Jo gets a visit from a man who has shocking news related to her dead sister.
With the help of D.B. Russell from the Las Vegas crime lab, Mac is able to identify the people who kidnapped Christine. But will he get to her before it's too late?