In the series pilot, Lt. Mike Torello (Dennis Farina), the head of Chicago's Major Crime Unit in the early '60s, has a personal interest in a case involving the son of a close friend who gets mixed up with mobster Ray Luca (Anthony Denison.
Here we meet the three major players of the series: Lt. Mike Torrello, head of Chicago's Major Crime Unit(MCU); Ray Luca, a young hood about to make his mark on the underworld; and David Abrams, an idealistic public defender trying to bury his Mob-connected roots. As the story unfolds Torrello is working with Abrams to bring down members of Chicago's underworld while Luca is taken under the wing of Manny Weisbord; one of Chicago's most powerful crime figures. As events proceed Torrello and Luca each become aware of the other's existence. Torello realizes that there is a new player that he must bring down.
A psychopathic killer becomes the Major Crime Unit's top priority; Torello learns of Luca's plans for a nationwide sports-betting operation; Julie wants to start a family.
Torello introduces himself as a “friendly” cop to one of Luca's burglary crew after the crew's new man kills a woman; and the Torellos get some good news.
To ensure his takeover of a sports-betting operation, Luca sends Holman to St. Louis, where a politically motivated sheriff is overly friendly to Holman's MCU tail.
Luca's superiors blame him for the debacle in St. Louis, prompting him to seek advice from Abrams; Torello leaves a gift for Luca after the MCU halts his truck hijackings; Julie enters the hospital. Guest stars Miles Davis, Michael Madsen.
A reporter helps Abrams in his defense of a tenant who assaulted a slumlord; Torello promises a despondent Julie a vacation. Guest stars Ving Rhames, Pam Grier.
The Torellos take what may be their last vacation; the FBI corners Holman in Toledo; Weisbord's expansion plans include Torello's war buddy (Mark Hutter). Guest stars Pam Grier.
A lawyer thinks Torello is involved with Kehoe and Luca, who moves to have an indictment against himself and Bartoli quashed. Guest stars Christian Slater, Eric Bogosian.
Torello mourns his loss, then searches for Holman; Susan is attacked while doing a story on heroin; Luca declares himself the sole Chicago fence. Guest stars Pam Grier.
A small town honors the MCU after the bust of a jewelry-heist team connected to Luca; Krychek takes a special interest in one of the busted henchmen. Guest stars Gary Sinise.
Mike Torello's obsessive pursuit of Ray Luca is recalled through flashbacks. Guest stars Michael Madsen, Lorraine Bracco.
Torello has to split his men up when a woman is held hostage by a crazed gunman just as Holman is spotted in an Indiana diner (Ted Levine). Guest stars Fred Savage, Michael Madsen, David Caruso.
The Feds buy Holman's claim that Torello is a dirty cop; Joey interrupts Luca's visitors; Luca learns Holman may still be a legal asset despite causing his impending indictment.
Torello (Dennis Farina) is subpoenaed upon his return from the West; Luca can't coax Abrams to his side; Weisbord's future plans are challenged by others wanting profits now.
Abrams (Stephen Lang) helps Torello (Dennis Farina) with his testimony about Holman's charges; Weisbord calls a council to deal with dissenters; Luca says his goodbyes.
Torello (Dennis Farina) asks a debtor being strong-armed to help him link slot-machine skimming and loan sharking in the casinos to Luca (Anthony Denison).
Luca tries to install his candidate for union president during a strike; a former employee crosses Luca's path; Torello thinks there's a traitor in his ranks. Guest stars Stanley Tucci.
Torello's relationship with the ex-wife of one of his men uncovers disturbing information about the man, who allows a slip in the force's security. Guest stars Julia Roberts.
Luca sends Taglia and Holman to sabotage a neighboring casino; Torello's inside man witnesses actions that could bring Luca down.
The now aggressive strike force manufactures dissension within Luca's ranks and takes advantage of his excesses. Guest stars Deborah Harry.
Torello (Dennis Farina) anticipates a move by Luca to get to Taglia (John Santucci) or the jury. Later, Torello heats things up between Luca and a hood who, with Weisbord's support, tries to move in on his turf.