The firefighters take on a rival firehouse for touch football bragging rights; Brooke files for divorce; Jimmy worries that he may be a father again.

No one can find Bosco after a sexual assault suspect is found dead. While Bosco spends time with family, Yokas, Ty and Sully try to clear him as a murder suspect. Still locked in a custody battle over Joey, Jimmy and Kim meet with a court-appointed evaluator and plead their cases. Alex tries to stay busy to avoid dealing with her feelings about her father's death.

During the investigation of the gang shootout, the police officers are questioned and presented with evidence that suggests that Ross was killed by friendly fire; Carlos learns that Vangie is dead and that he is the father of the baby her sister leaves at the firehouse; on the first anniversary of Bobby's death, Kim quarrels with Jimmy over her visitation with Joey and confronts a female gang during a call; and Doc is visited by the father of a former patient whose debilitating injury may have been caused by Doc's error during treatment.

Yokas and Bosco try to find a missing boy whose parents think has been taken by a registered sex offender; Sully prepares to be questioned about his wife's background

Monty and Joy hook up. Miguel witnesses one drug dealer murder another, and becomes the dealer's next target. On his first day back at work, Sully rides with Faith, who is put off by his short fuse and bad attitude. When he leaves a prisoner unguarded and uncuffed, Faith tells him to go home because he's not ready to be back on the job. Sully gets drunk and goes to his mother's nursing home. Sobbing about Tatiana, he tries to batter down the door when the receptionist won't let him in and calls the police. After Hancock arrives on the scene, Sully mouths off to him about Nancy in front of the other officers who are there to take him home.

Sully hits bottom when Ty washes his hands of the partnership after Sully's drinking goes completely out of control; a thief strikes fear in the hearts of the police when he phones in false ""officer-in-need-of-assistance"" calls to cover his fur store robberies; Faith and Maritza go at it after Maritza's lonesome cowboy tactics nearly get another cop killed, and Faith is forced to shoot a perp to save Maritza's life after she goes after the perp without backup; Doc has an unpleasant encounter with Joy's father; Faith is disgusted when she finds out about Bosco and Maritza, and Maritza confirms that she put Bosco in front of a lie about a dying declaration to obtain a conviction on a drug dealer; Ty overcompensates for Sully's inattention to the job by becoming a ""supercop"" with an eye to getting a gold shield.

Kim is invited to a party by Noble. Noble is arrested through an undercover operation. He becomes an informant and helps Cruz and Bosco bust a Meth ring. Faith officially requests a new partner. Emily and Faith face off about Eric.

Yokas clashes with her mother over her recovery; Maritza is back on the job, but unhappy that she's back in the bag and handing out parking tickets; Ty and Sully discover a truck carrying sick illegal aliens and end up scouring the city to track down one of them who escapes after it's determined that the aliens have a highly contagious and potentially fatal disease.

Sully kills one of the perps and shoots the denotator out of the hand of Frank Morgan, the bomber; Doc goes ballistic when he comes upon the scene of an accident involving his old rig and a city bus, and physically assaults Eugene; Public Morals raids Dr. Chow's office, and Maritza is forced to reveal her rape to keep Thomas Warner from being released on a D.A.T.; Ty gets Frank Morgan to flip on Gary Barnes, and Barbara promises Morgan that she will make sure he gets the death penalty for killing her housekeeper and driver; Kim and Carlos refuse to back up Eugene after he files a complaint against Doc, prompting Eugene to quit; a distraught Faith, still plagued by flashbacks of the shooting, asks Fred if they can get out of the city for a family vacation; Warner confesses to raping Maritza while Bosco is transporting him to the Tombs; Carlos is horrified when Doc admits that he accosted Eugene at his house because he ""killed Taylor""; Bosco turns Warner over to Maritza, who gets her pay

Jimmy gets a promotion to a rescue squad in Brooklyn; despite their new captain's assurances, Doc suspects that he intends to close down the house; Sasha insists upon pursuing an investigation into the beating death of a hit-and-run driver after Maritza uses the confession of an innocent man as her stepping stone to an Anti-Crime reassignment; after Jimmy is trapped in a warehouse fire, Kim reassesses their plans for a future together; Rose's serves a customer at the bar who shares a past with Bosco.

After she realizes that telling the truth will mean and prison sentence and never seeing her children again, Faith reluctantly agrees to go along with Maritza's cover story that she shot Mann as he was trying to stab Maritza; Yoshi slips out of the cuffs and into the wind; Sasha and Ty hook up; Maritza gets a tough new boss who's been charged with keeping her on a very short leash to curb her renegade ways; Faith goes ballistic when Fred has her served her with divorce papers at the station house; Swersky shuffles the partnerships, and assigns Faith to ride with Sully and Sasha to ride with Ty; Maritza gets an anonymous call that there's an I.A.B. plant in the house who's after her, and she immediately suspects that it's her new boss; Faith decides to turn down the promotion to detective that she's offered for saving Maritza's life until Sully reminds her that the new assignment will improve her chances of getting custody of her children; Bosco's surgeon gives Faith a devastating progn

Maritza calls on her own experience to persuade a rape victim to identify his attacker and sign a complaint after she collars the perp and gets a confession; Ty's prison visit to his father's killer has devastating consequences for both of them; Faith frantically searches for her son when Fred's girlfriend reports that he's missing; the former partners come to blows after Ty accuses Sully of being part of the cover up in the death of Ty's father; both Ty and Sasha deny telling I.A.B. about the knife when Maritza questions them; Sasha uncovers further details about the conspiracy to murder Ty's father and the ensuing cover up.

Monroe and Bosco deal with an angry mother on welfare who shoots up the welfare office, Davis and Finney stake out a man and take down a prostitution ring, Faith deals with Emily, Cruz and Monroe recieve bad news about their health.