Vinnie nearly blows his cover when he becomes obsessed with finding out who killed his cousin, causing Frank to threaten him with dismissal. Frank desperately wants Vinnie to concentrate on nailing the Zaratzos, who are trying to arrange a drug smuggling deal with Sonny, because they killed one of Frank's agents.

After several deals go sour, Sonny starts suspecting Vinnie may be a plant. Frank orders Vinnie to drop the case when he finds out the local police have an informer in Sonny's operations. Sid has Frank picked up and tortured, but Vinnie and undercover cop Karen Malloy rescue him. Karen's disappearance points the finger at Sid as the leak.

After his mother is mugged in Brooklyn, an enraged Vinnie sets out to find the punk who did it, but when he visits his mother in the hospital, it breaks his heart that she still won't forgive him for his life of “crime.”

Sonny’s cruel punishment of a lounge singer who wants out of his contract triggers a cascade of events that leads to Vinnie’s being photographed with McPike — a photo that is to be delivered to Sonny.

Sonny’s impending marriage to a syndicate boss’ daughter begins a supposedly businesslike realignment of “families,” but Vinnie learns that the wedding is a pretext for a bloody gang war.

An outraged Sonny Steelgrave accuses Vinnie of betraying him to his arch-rival, then realizes the devastating truth — that his paisan is an undercover Federal agent.

In the aftermath of the Steelgrave case, Vinnie tries to vindicate himself of his lingering feelings of betrayal and disloyalty by risking his life to save an old friend from the Brooklyn neighborhood who has a contract out on him.

Vinnie’s assignment to check out a contract killer leads him into a huge global contraband syndicate — an operation that far exceeds the scope of the Steelgrave family — overlorded by brother and sister Mel and Susan Profitt.

Vinnie, now a bodyguard for the Profitts, gets his first trial by fire when Mel Profitt, the brilliant but paranoid overlord of an international crime empire, disrupts the wedding of an associate, who retaliates by kidnapping Susan.

Vinnie tells Mel Profitt he is leaving to go home to New Jersey, but Mel offers him the biggest cocaine distribution network in the country — a plum that Vinnie feels is too juicy for any undercover cop to turn down.

Mel’s desire to buy a baseball franchise is two-fold: he wants to play on it, and he wants to take it away from an old business associate who cheated him in a Mexican drug deal. When Mel’s former girlfriend shows up, begging for readmission to the Inner circle, he humiliates her, using her as a sexual pawn in a power game with a rival, but for Vinnie, forced to watch it happen, the worst is yet to come.

When some of his munitions contacts begin drying up, Mel decides to blackmail a French Deputy Minister of Defense into supplying him with the weapons he needs.

Hiding out in Vancouver after the fall of the Steelgrave empire, Aldo Baglia sees a photo of Vinnie in the paper and decides to even the score, sending Vinnie into a coma from two serious gunshot wounds. Roger, using his CIA contact, tracks down Aldo.

After rejecting an offer to finance a coup d'etat in the Caribbean, Mel Profitt becomes obsessed with a supposed voodoo death curse, and Vinnie, horrified, can only watch as Mel’s personality begins to disintegrate.

After Susan is arrested for Mel’s murder, Vinnie refuses McPike’s order to pull out of the Profitt case, because Susan, who has seemingly lost her grip on reality, has told him she is pregnant with his child.

With Mel and Susan Profitt undone, McPike begins dismantling their empire, but Vinnie demands to stay on the case to get to the bottom of Roger Lococco’s ties to a rogue CIA operation to stage a Caribbean coup d’etat.

Roger Lococco in effect signs his own death warrant by testifying to a Senate committee about a cabal within the U.S. intelligence community, but to back him up he needs Vinnie to testify as an O.C.B. operative — testimony that would end Vinnie’s career as an undercover agent.

While keeping vigil over Rudy, Vinnie learns that Grosset's father-in-law was also hit, setting up a power struggle within the mob. Albert courts Vinnie's alliance by letting him in on his plan to smuggle millions of dollars worth of heroin into the country. Vinnie goes to the Commission and demands Rudy's seat at the table. (source: http://www.plasticcow.com/wiseguy)

The tension mounts between Cerrico and Grosset over control of the garbage collection business. Grosset forms an uneasy alliance with Chinatown mobster Chin. Carlotta urges Rudy to get better and get Vinnie out of the middle of the impending mob war. The OCB closes down the explosives factory in Chinatown. Gina Grosset kills Chin. After an assassination attempt at the opera, Amber tells Vinnie to move out. (source: http://www.plasticcow.com/wiseguy)

Frank wants to pull Vinnie off the case when he finds out that D.A. Peter Alatorre plans to expose Vinnie as the head of the Commission in a news conference. Albert is distraught when his son is expelled from school because of his recent press coverage. Rudy calls Alatorre to his hospital room to show that he is back in the country, taking the heat off Vinnie. (source: http://www.plasticcow.com/wiseguy)

Rudy discovers Joey's plan to kill him, Albert and Vinnie, so sets his own plan into operation by convincing Albert he must kill Grosset. Albert and Joey have a showdown that ends with Joey dead and Albert in jail for his murder. Wanting her due, Gina sets up a meet with the Commission to offer them Albert's heroin deal. When Frank easily affects the arrest of the Commission, Vinnie begins to suspect that Rudy set everything up for them. (source: http://www.plasticcow.com/wiseguy)

Frank and Dan urge Vinnie to try and reconcile with Amber. At their urging, he goes to her, they make love, then she demands that they see a counselor. Following their therapist's advice, they go away for the weekend, where they both realize they're too involved in their careers to be able to maintain a relationship with each other. (source: http://www.plasticcow.com/wiseguy)

When a local priest finds a box that belonged to Pete, he takes it to Vinnie, who finds a diary of his father's inside. As he reads it, he finds out about a dark episode involving his father and the local mob. The episode uses black and white film and familiar faces to bring John's diary to life. (source: http://www.plasticcow.com/wiseguy)

Vinnie and Frank try to cheer up Dan, who's depressed about becoming a grandfather. When Lauren finds a phony check in her husband's pocket, she asks Dan to investigate, and he uncovers a scam a local builder is using to bilk his insurance company. The builder is shut down, throwing Stephen out of a job and making him decide to leave town. (source: http://www.plasticcow.com/wiseguy)

Vinnie attends his 15-year high school reunion and bumps into two old friends, one a mob lawyer and one a detective. Vinnie is torn between telling Denise he's a cop and protecting his cover. Frank tells Vinnie that Denise has bugged his house, making Vinnie furious and determined to teach Denise a lesson. Denise and Mooch get married. (source: http://www.plasticcow.com/wiseguy)