Nash and Joe are in undercover Western garb as Teddy and Carlos, respectively, to bust an India animal smuggling ring bringing in things such as giant python snakes. The SIU closes in, as Arif Upal tries to get away in a truck. Nash and Joe blow out the truck tires, but Arif dies choking and gagging mysteriously.
Arif has died from a cracked vial of VX nerve gas, and there are another 10 pounds of VX liquid in the back of the truck. Nash and Joe locate Arif's brother VJ in a country Western bar. Pepe (the former manager of Joe's gay bar) also works there. VJ is taken in for interrogation.
Meanwhile, a young woman named Maria Renaldo suspects that Joe is her father. Twenty years ago Joe donated sperm, and Maria has shown up as she is about to get married. Inger hears Maria's story (but not about Joe's involvement), and to the chagrin of Joe, Inger invites Maria to stay with them. Cassidy contacts Evan, and they make a secret date to see the movie TITANIC.
Nash and Joe question VJ about who wants to buy ten gallons of nerve gas for two million dollars. Facing extradition and beheading in his own country, VJ gives up the cellular phone number of Pamela Smith. Pamela claims her phone was stolen, and she makes a pass at Nash. Nash smells a rat and has her checked. Pamela has a PhD in chemistry, and her father was a sixties radical who died in prison after 24 years in lock-up. Pamela has a partial motive of revenge.
Nash and company intercept at OPC Chemical, where a clerk has called about selling the suspect chemicals required to make VX. Nash recognizes one of the buyers (the other has escaped) as undercover cop Mike. Mike reveals that Pamela has some sort of plan already in progress. Nash decides to use Mike as bait to catch Pamela.
Joe has grown fond of Maria, and they agree to take a blood test to determine if Joe really is her father. Joe agrees to be her father even if the tests are negative, and to be at her wedding. The blood test turn out negative - Joe is not Maria's father.
Pamela is already on to the trap; she calls up Nash and warns him to evacuate the SF downtown area from Second to Fifth Streets within four hours. With the evacuation as diversion, Nash and the SIU deduce that Pamela's target is the corporate headquarters of a jewelry store. Nash and company intercept. Nash prevents the nerve gas bomb from being set, as Pamela and her gang rob the gem vault. A stand-off is reached when Pamela threatens to kill everybody with an extra vial of VX gas, but Nash cuts the hose to her gas mask and arrests Pamela.
Pepe helps with Maria's wedding arrangements, as Nash and Joe arrive to give away the bride. Evan decides to cool their romance, but Cassidy seems unwilling.
For more, see commentary for Episode 51