The team struggles to narrow down a suspect when threats against a company that endangers sharks turn deadly; Kamekona tries to earn his helicopter license.
The team reopens the 1983 case of a teenager who was killed before he could get justice for his slain girlfriend.
Sipowicz has to make some tough decisions as he starts a new chapter in his life.
Walker pledges to pay a Vietnamese gang back for the murder of his old martial arts instructor's son, who was an undercover cop.
Simone and Sipowicz probe a drive-by shooting; Russell and Kirkendall learn that a baby was shaken to death; Fancy presses for a killer's confession.