Nash, while investigating an apparent gang killing, discovers that the weapon used for the job is the Army's newly missing man-portable, antitank system: The Javelin. Nash is assisted in the investigation by Sandra McCormick whoose career is on the line if the Javelin is not recovered.

Nash must stop a sniper terrorizing the city by shooting victims at random. A rat infestation forces Joe to confront his ""landlord,"" Nash, about the problem. Evan proposes to Cassidy, but in the wake of a serious traffic accident, Cassidy is left fighting for her life.

Nash and Joe are plunged into the underground world of steroid-crazed body builders when they investigate the murders of three body builders. Nash and Caitlin struggle to define their relationship as Cassidy struggles to get her feet back on the ground after her accident.

The Governor is missing, and Nash and Joe lead the ""off-the-record"" investigation into his disappearance. Caitlin, shut out, is determined to find out what he's up to. Joe and Inger attend a charity auction as a man's proxy to get on his good side, but overpay and get stuck with the art project.

A sleep-deprived Nash must track down an ingenious bomber targeting a corporation he feels has wronged him. Cassidy tries to conceal her nudity in a school play.

Handcuffed Skip Osaka jumps out the back of the moving 'Cuda. Nash and Joe give chase. Skip runs up a fire escape onto a power line. The line breaks, and Skip falls through a window. Nash and Joe place him in the trunk of the 'Cuda, and bring him to the SIU. A surprised Nash, Joe and Harvey discover the SIU barge is being towed away by a tugboat. The Head of the MCD, Reuben Banks, drives up and informs Nash the SIU has been temporarily shut down.

The SIU is disbanded by MCD: Nash and Joe are assigned to Park Detail, Harvey to Homicide, Evan to Traffic, and Caitlin to Vice. At the Civic Center Park, Nash and Joe meet Colonel Culpepper, drug addict/transient, and Phil, the phony Vietnam veteran. The Colonel is shot dead in the park. Harvey and his new partner, Inspector Riley Webber, investigate the murder.

Evan and Cassidy have set a wedding date. Harvey is best man, and he plans the bachelor party. Nash and Nick are informed, and Nash gives his blessing. Father Nick gives Cassidy her g

Cassidy finds an apartment, only to be mistaken for the previous renter who has stolen money from drug dealers. Lonely Joe carries on an online romance, but the other ""woman"" turns out to be Pepe. Evan bottoms out in his broken relationship with Cassidy