A man dies when he falls from a vacant high-rise building. When a new medical examiner, Shannon Higgins arrives at the scene to inspect the body, she is shot in the head and dies almost immediately, triggering a gunfight between the Miami PD and the unseen shooter. The investigation reveals the man was involved in illegal ammunition sales. But the case gets personal when Horatio links the victim to Kyle's stepfather. At the end of the episode, Horatio is mortally shot from an unknown killer. Then the killer himself sends a message to Wolfe: "It's done".