Cassidy finds herself in the middle of an SIU case when she becomes the victim of a high-climbing jewel thief and Nash begins to close in on the suspect: her new boyfriend. Stacy becomes concerned that Nick is being turned into a lab rat at the university where he has volunteered for a research study.

The episode was rated 8.19 from 21 votes.

Nash and Joe risk causing an international incident after British consulate workers fake the death of a convicted killer in order to use him for their own nefarious purposes. Joe resorts to extreme measures in order to get Lucia accepted into an ultra-elite school.

The episode was rated 8.38 from 16 votes.

Nash must protect Lynette (Suki Kaiser) from ruthless Hong Kong mobsters when she unknowingly becomes involved in an Asian forgery ring. When Lynette's old flame, Brian, mails her a flawless forgery plate for $100 bills, Nash must protect her from the brutal Hong Kong gangsters from whom the plate was stolen. When Brian unexpectedly appears at Lynette's door, their attraction is re-ignited, but he soon becomes the chief suspect in Nash's investigation into the forgery ring, run by an Asian crime syndicate. Meanwhile, Joe's visiting father (Ismael Carlo), a sheriff from New Mexico, drives Joe crazy with his meddling until he uses his own brand of Wild West sleuthing to expose a murderer in Joe's apartment building.

The episode was rated 8.60 from 20 votes.

Nash and Joe follow the trail of a criminally insane mental patient who believes he is the nemesis of Sherlock Holmes. Joe hires a baby nurse who takes over his life.

The episode was rated 8.64 from 25 votes.

Rick Bettina returns as the head of the S.I.U. Joe is accused of stealing 3 million dollars from a suspect. Harvey has a torrid affair with a woman he once arrested.

The episode was rated 8.65 from 20 votes.

Bettina is accused of killing a high-class call girl. Only Nash can help Rick find out who framed him for murder. Meanwhile, a man masquerading as Joe has become a major romantic figure in town (with Joe's credit cards), much to Inger's chagrin.

The episode was rated 8.79 from 24 votes.

Nash and Joe team up with a tough-talking NYPD Special Crimes Detective (Penny Marshall) in order to track down a famous fashion model's deadly stalker. Meanwhile, Harvey helps Evan track down his lost badge before Nash finds out. A shopping trip doesn't turn out the way Nick and Lynette had planned.

The episode was rated 8.95 from 22 votes.

Willie Nelson plays Earl Dobbs, a convict who gets a furlough from San Quentin to help Nash and Joe catch his former crime partner.

The episode was rated 9.00 from 30 votes.

A sniper terrorizes San Francisco on Halloween as a city-wide Blue Flu forces our SIU detectives to assume beat cop responsibilities. Joe tracks down a hard to find Halloween costume for Lucia.

The episode was rated 9.03 from 30 votes.

Sultry criminal and Nash's ex-girlfriend Tamara VanZant resurfaces, this time as a player in a plot to sell stolen plutonium. Joe plans to make a mint by marketing a secret-recipe salsa that's been in his family for generations. Robert Rodriguez stars as Joe's commercial director.

The episode was rated 9.05 from 20 votes.

Nash and Joe investigate several brutal drug-related gangland murders and follow a complicated trail of clues to a surprising suspect -- Bruce Sutcliffe, a multi-millionaire from a well-respected San Francisco family. When Nash discovers that Sutcliffe has been a major drug kingpin for years, he risks his job and his life to expose the magnate's secret life. Meanwhile, Evan and Bettina go undercover in a transgender beauty pageant to trap a blackmailing murderess who pretends to be a man impersonating a woman.

The episode was rated 9.10 from 29 votes.

A fugitive is released from prison by mistake and seeks revenge on Michelle. Nash teams with Michelle to capture him. Meanwhile, Nash refuses to partner with Joe on an off duty case to protect a sportscaster being blackmailed, so Joe chooses Evan.

The episode was rated 9.13 from 30 votes.

Nash and Joe are on the trail of a ruthless gang of thieves threatening to release the lethal nerve gas over downtown San Francisco unless the area is evacuated. Once the area is cleared of people, the criminals plan to move in and rob the banks in the area. Racing against time to capture the criminal mastermind behind this scheme, Nash is surprised to discover that the gang leader is Pamela Smith, a beautiful, brilliant chemist who created the deadly gas. Meanwhile, a mysterious woman appears who claims to be Joe's daughter from a college fertility experiment in which he participated years earlier.

The episode was rated 9.14 from 28 votes.

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.

The episode was rated 9.15 from 26 votes.

Nash gets involved with Irish terrorists, as well as his ex-wife Kelly (Serena Scott Thomas). Meanwhile, Joe looks after a party-minded Arabian prince awaiting a heart transplant.

The episode was rated 9.16 from 25 votes.