Nash and company foil a jewelry heist ring posing as firemen. Nash hits a pedestrian and gets sued. But Caitlin has misplaced Nash's auto insurance bill, and he blames Caitlin.

Nash begins to believe that a 17-year-old boy involved in the Southeast Asian drug trade may be his missing brother's son; Cassidy starts dating a plastic surgeon and considers getting breast implants.

Nash and Joe meet Lyle who tells them the secret location the SIU barge has been towed to. Joe returns Lyle's chihuahua Ginger who has been held hostage in return for the info. A truck deliberately rams into a van containing three prisoners. Nash and Joe arrive at the accident scene, with Nash figuring out that a phony paramedic van has taken the three prisoners in a successful escape attempt. Nash, Joe, Harvey and Evan arrive at the empty and disconnected SIU. The Mayor has granted a one week reprieve pending the Police Commission hearing. If Nash and company catch the three escaped prisoners, the SIU will be saved. Head of MCD Reuben Banks daughter Gina's immunity deal is also dependent upon the return of one of the escaped prisoners - Gina's former boyfriend, Jimmy ""Shank"" Brasher. The other two escapees are Darnell Galloway and Elliot Wong. Gina is kidnapped by Brasher. Jake Cage of Fugitive Recovery is already on the case, beating Nash to interview Mr. Footman, owner of the stolen

Evan puts himself under suspicion after he takes $40,000 of drug money during a bust; Nash and the SIU take down a drug dealer. Nash and Joe guard a chimpanzee, while Jake Cage goes undercover as an animal extremist.

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.

A juror becomes a vigilante avenging murder victims. Caitlin and Joe go in on a donut business venture. Evan is arrested and calls Cassidy; Cassidy finds a new boyfriend.

Wearing his brother's uniform as a motorcycle cop and impersonating a police officer, a deranged man imagines and talks to his dead brother. Nash adjusts to his break-up with Caitlin; Nick fails his driving test; Cassidy asks Evan for help to move back into a Berkeley apartment.

Nash goes undercover to stop a high-end heist artist. Joe helps a restaurant critic who receives death threats; Evan is back in the SIU; Caitlin takes an administrative job within the department; and Harvey helps out a troubled 12 year old boy.

Nash and Joe arrive in Las Vegas, and locate assassin Roy McNeer's hotel room. His food is still warm, as Nash and Joe spot McNeer in a casino. Nash and Joe give chase, but are held up by the hotel security guards, as McNeer escapes. Nash and Joe check into the hotel - Pepe is the concierge. They locate McNeer's girl, Vivienne Reed, and she agrees to tell Joe if McNeer calls her. The truck full of half a billion in laundered cash is hijacked. The two thugs contact Tony B to ransom the truck for $50,000. Tony B and the SIU meet them and get the truck back. Harvey, Evan, Officer Ronnie and Tony B go to Las Vegas with the truck full of money. Jake Cage shows up in Las Vegas too, with orders from Caitlin and the Mayor's Office to bring back Nash. But Jake agrees to help Nash instead after an altercation. Nash meets with Ellen Holiday. She fills Nash in on the rest of the DEA investigation. Jimmy Z works for a drug king pin coming in from Shanghai - they have ordered the hit on Police Chief

Nash's former lover Tamara Van Zant forges his name on a marriage license and claims to be married to him in order to protect herself from a thug out to kill her; Nick pretends to be romantically involved with a lesbian friend to deflect suspicion from the woman's son, a high-profile gangster from Philadelphia.

A serial killer who picks up passengers in a cab and then murders them stalks the city; Cassidy struggles with whether she wants to continue to be a cop.

When a reporter is murdered while covering the new ""French Connection"", Nash comes face-to-face with a startling revelation - his brother, a Vietnam MIA, thought dead for the last 24 years, may be alive and in San Francisco. Meanwhile, Lisa's sister, Lynette, arrives to house-sit at Lisa's indefinitely.

When the ruthless high school dropouts go on the crime spree, Nash's search for the couple leads him into an underworld of heavy metal rock and satanic worship. As the intensity of the crimes increases, Nash must race against time to stop the desperate duo before they murder all the enemies on their ""grudge list."" ; Stacy and Nash meet Nick's long-lost love from the war years; Joe finds Evan and Cassidy in a compromising situation.

Nash finds himself defending Caitlin when she's the main suspect for a murdered CIA agent connected to her mysterious past. Joe begins working out with the trainer from hell. Cassidy and Nick enter a tango dance contest.

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.

Nash and the SIU must re-open a serial killer's case file when a body is discovered and it appears to be Angel's. Bonnie, Harvey's ex-wife, returns with an interesting proposition. Joe and Caitlin square off as rival soccer coaches when their teams enter the playoffs.

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

A psychologist establishes an insanity defense for her patient while they plan bank robberies. Nick wants to become financially independent by marrying a rich widow. Evan shows up for work drunk, forcing Harvey to confront Evan's substance abuse problem.

Nash and Joe get a tip from Tony B that there is a hit out on Chief of Police Frank Girard. But it's already too late, as the Chief's car is shot up - the Chief and his driver are killed. Nash and Joe arrive to find the carnage. The Chief was a close friend of Nash's. There was one driver, one triggerman, using a bright red Impala. The Impala crashed into a taxi, leaving behind a paint sample. Thanks to Caitlin's suggestion, the SIU and the Embarcadero station are sharing office space in the barge. There is total chaos, as Joe is forced to share a desk with Jake Cage. Tony B is interrogated. Tony B has a new business - Bay Area Switches. The trucking business is really a front to ship money to Las Vegas to be laundered. Tony B's contact is Ellen Holiday. Holiday is in contact with the assassin of the Chief and with Jimmy Z, head of the money-laundering operation. Holiday is arrested and questioned, but she reveals nothing. The red Impala is found, tracked to a Melvin from a wrecking ya

An old nemisis of Nash's breaks out of prison. Joe finds a new house through Ulla, makes an incredible deal on it, but it turns out to be a disaster. Harvey's new partner, Antwon Babcock, joins the SIU.

Nash and Joe are on the trail of a high profile robbery ring that targets San Francisco socialites. Nash runs into Angel when Belinda Cruz hires B&D to prove her sister's pregnancy (she's a nun) is not a virgin birth. Joe enlists Nick to build a speed bump in front of is house.

Nash and a Federal marshal (Philip Michael Thomas) are taken hostage by a Miami drug lord who wants to exchange them for a witness who's scheduled to testify against him in court; Joe tries to get out of being audited by the IRS.

Harvey becomes attracted to a fellow ""Deadhead,"" a mysterious woman who is the target of a murderous stalker; Joe is promoted to Lieutenant, but discovers that his new duties mostly involve paperwork; Nick injures his leg and makes life difficult for Nash and Cassidy, who are just trying to take care of him.

A famous mystery writer offers Joe $350,000 for ""Mr. Woody"", while he waits it out (hoping to get more money) meanwhile Harvey stumbles onto a robbery durring a Phil Lesh concert at the Fillmore pulled off by 2 women (Jill Ritchie & Vanessa Dorman)and all Nash and The SIU Team have to go on is that the getaway Harley has a unique design on the side. Finally getting the papers to send Betty Ann on her way, Joe presents them to Nash for his signiture, but before he can sign it and get her outta there, she uncovers that she's found some.....curious irregularites in the SIU files, and it seems that the SIU has a mole. and also Boz (Christian J. Meoli) and Antwon do some P.I. leg work for Nash and Joe to find who stole a demo tape from Dickie Lerner (Rickey Medlocke), a record producer, and it is Rachel's birthday. The last episode i remember seeing out in the west coast.

Nash and Joe have a task of escorting a secret key witness from the Witness Protection Program to San Francisco to testify in an important SIU-related case. They fall under gunfire. Nash realizes there's a leak somewhere on the prosecution's team. He enlists the help of Stacy to protect them until he can solve who it is and get the witness safely to San Francisco. Cassidy is stood up for a date and decides to go out with J.J. instead.