The body of a man involved in recovering sunken treasure is discovered pinned to the wall of his new cabin cruiser by a spear fired from a spear gun at close range.
Maggots dropping down to the neighbor below from an apartment being renovated allow discovery of the body of Peg Donovan. Her skull was smashed with lumber, but she survived. Horatio's only logical suspect is Mason Shaw, who was convicted for raping her, and maybe planning from jail to prevent her testimony ruining his up-coming parole hearing. The team must find proof beforehand if he orchestrated everything from his Georgia prison somehow manipulating his own son - Chuck Shaw.
A young girl is kidnapped from her bedroom in the dead of night, and when an arm shows up without the body attached Horatio must determine if it belongs to his victim or a new one.
The two young owners of a city bar are gunned down after hours and another man is wounded in the attack, which was allegedly committed by a masked gunman. Calleigh's dad announces he is now a public defender and needs her help with a murder case.
A man is found dead, his throat slit, in his office. Meanwhile, Raymond Caine's case is re-opened and eventually solved when Horatio Caine finds more evidence about the murder.
In the marina, a shark fatally bites Cindy Castiano, attracted by a bleeding earlier shot wound. She worked for P.I. Bruno Gomez to entrap wealthy men. So the suspects include victimized adulterers Carl Purdue, who as ruined and threatened her life, and Matthew Warner, who believes she loved him. Eric tries to pussyfoot after finding MPD detective Frank Tripp's fingerprints and his name on a client list.
A plastic surgeon is found dead, hanged in his own apartment. Meanwhile, a husband of his former patient, who died from complications during a routine surgery, is suing the clinic for the death of his wife.
A slow burn in the Everglades that turns on itself yields a body different than the one Eric and Alexx were brought out for, and endangers their lives; Horatio thinks he's found a sexual predator, but now he must prove it.
A money van carrying $3.2 million is robbed. One of the two drivers is shot dead. Caine manages to track the stolen money, which turns out to be counterfeit.
A rap concert is unceremoniously ended when a shot is fired by an unseen gunman. A body guard is instantly killed and the singer is wounded in his right arm.
Examining the bloody murder of a Miami father and his wife, which the teenage daughter survived, Horatio's team soon finds trails to a car rented by a man who flew in from New York City. There Horatio teams up with his CSI counterpart Mac Taylor, who is examining a cop-killing, possibly by the same murderer. Together they follow him, work out what erroneously drove him to Miami and arrive at an analogous crime scene, where rich Michael Hanover and his wife were killed, badly stabbed adolescent son Mike Jr. The matter of key access suggests some involvement of the janitor.