Don Fischer

Dexter and Lumen’s plans are momentarily thwarted when Dexter’s forced to do damage control after he concedes that someone, outside of Miami Metro, has taken an interest in them. Debra’s speculation on the missing Barrel Girl suspects begins to take shape. Quinn finds himself more involved in a homicide than he'd like to be.

Don and his team must stop a sniper who goes on a killing spree in Los Angeles. Racing against time to find the sniper, Don calls in Agent Edgerton (guest star Lou Diamond Phillips), a senior Sniper Instructor from Quantico, to assist on the case, causing Charlie to feel insecure about his role as special consultant to the FBI. Feeling animosity towards Agent Edgerton at first, Charlie learns from him that human behavior could make his mathematical equations useless. Instead, Edgerton encourages Charlie to get inside the head of the killer.

Emily helps Nolan's blushing bride deal with the skeletons in her closet while Victoria contends with a mysterious new socialite.

E-mails and text messages trigger a mass gathering of students to perform a random task on a golf course. However, as the crowd disperses, the body of a high school student is found.

When a conspiracy-obsessed woman is found dead, the CSIs investigate and discover that some of her theories may have had some truth to them. (TV-14)