UC: Undercover

Jake and Alex go undercover to crack a group of thieves who stole a multi-million dollar heroin stash from a police lockup. ""Sonny"" Walker's (William Forsythe) girlfriend (Angie Everhart) (see previous episode) seeks to continue his operation and confronts Cortez (Steven Bauer), an imprisoned associate who was Alex's lover before she busted him. Alex is torn between her feelings for Cortez and her team leader, Keller (Grant Show), who also has romantic feelings for her. Oded Fehr joins cast.

The Attorney General's (Kurtwood Smith) son is kidnapped by a vengeful Columbian drug chieftan (Tomas Milian) whose son (Maurice Compte) is on death row. Donovan must battle his rival operative (Andrew Divoff) and the Attorney General's love for his son, which overrides logic.

Jake is dispatched to infiltrate Quito Real's (Ving Rhames) organization, and Alex to infiltrate the equally notorious organization of Benny Li (Stephen Chang). Quito is looking to expand his organization by teaming with Benny Li (guest star Stephen Chang). Elsewhere, unknown to the team, Carlos Cortez (Steven Bauer) is released from prison and the incarcerated ""Sonny"" Walker (William Forsythe) plots his own return.

The team goes after a gang that stole the Hope Diamond along with other priceless gems. While the stones are in the possesion of common thief Michael 'Mick' Vincent (Frank John Hughes), Alex posses as a buyer for a criminal dealer. Elsewhere, Jake has nightmares about testifying against crime boss Quito Real (Ving Rhames); ""Sonny"" Walker (William Forsythe) makes a deal that could get him out of prison, thanks to his girlfriend Carly (Angie Everhart); and Carlos Cortez (Steven Bauer) shows his feelings for Alex.

The team must find a master counterfeiter, who has allied himself with Quito Real and ""Sonny"" Walker, who maintains a vigil against Jake. Alex turns to recently released Carlos Cortez, but they can't deny their increasing mutual attraction.

Jake infiltrates an elite police unit that is dispensing vigilante justice.

Jake is posing as a long-time criminal and Alex as a prison psychiatrist when prison inmates stage a rebellion.

A bank heist gone wrong traps Jake in a hostage situation.

Donovan makes a temporary alliance with a local army officer in his pursuit of a notorious drug lord in Bolivia.

An operation against a ruthless drug dealer becomes more personal when the team's legendary mentor is killed.

A manhunt is underway for four extremely dangerous escaped prisoners: a cop killer, a sexual offender, a volatile lunatic, and a serial arsonist.