The CSIs are called out to investigate the murder of a young woman who was about to sign her divorce papers. Soon the husband turns out to be the ideal suspect. The only strange thing about the case is the murder weapon: a nailgun. However, things become personal for the team when Ryan is attacked and left injured after being shot in the eye with a nailgun while revisiting the crime scene.

A drug lord is gunned in his Coconut Grove mansion and a suspect arrested at the scene claims he sells marijuana to Delko. Stetler, from Internal Affairs, investigates and the case quickly gets personal when Horatio gets involved. As for the shooting, the CSIs learn that two gunmen may have been involved. Also, Calleigh makes a major decision concerning her job.