When gang-related gunplay goes down in an emergency room, Horatio and the team must find the gang members responsible. The evidence suggests that an orderly in the hospital recognized the wounded gang member, who possibly killed one of the orderly's friends and alerted gang members to his location. However, the evidence doesn't match up and the CSIs discover that a cheating girlfriend, not gang retaliation, may be behind the shooting. Meanwhile, Ryan questions a mother in the emergency room after her story regarding her child doesn't add up.

A former high school football star is murdered at a reunion, the CSIs must find the killer. The victim was the big man on campus in high school and there are a lot of guests at the reunion with reasons to resent him all these years. Now, the team must investigate everyone, from the head cheerleader to the school misfit, to see who held a decade-old grudge big enough to kill. Meanwhile, Horatio and Delko arrive at a crime scene and discover that it's already been processed, leading Horatio to uncover further information about his brother possibly being alive.

Horatio and the team are trying to figure out how to free an innocent young man after a harsh interrogation with Frank Tripp sends him to jail.