Jimmy's recovery complicates his return to the firehouse as he tries to take on too much, causing discord amongst his fellow firefighters over his all-consuming need to prove his abilities have not been lost. Meanwhile, Alex Taylor joins the firehouse and arrives with some baggage of her own.

A disturbing visit from his former high school girlfriend forces Doc to confront a horrible act he has hidden for years; Carlos struggles to pass a medical school qualification exam.

Faith, Bosco, Carlos and a wounded Doc find themselves trapped in an abandoned tunnel and unable to reach Central on their radios; the firefighters get into mischief during a long lull between calls; when the C.O. can't raise Bosco on the radio, Sully tries to cover for him.

Doc and Carlos attend a stress debriefing; Carlos meets up with Bosco when he's ordered to attend sensitivity training.

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.

After a despondent woman takes a walk off of an eight-story apartment building, the squad finds themselves in a race to transport both the woman's heart and a dying girl to a local hospital in time to save the youngster's life. The suicide hits home for Faith as she comes to grips with her own ongoing medical problems, while Doc expresses concern over the emotional effects this case will have on Kim, despite her constant reassurance that her accident was not an attempt to kill herself.

Even though his co-workers want to nominate him for the ""Paramedic of the Year"" award, a pensive Doc is disheartened as he considers his unfulfilled life. He later teams with Kim as they try to save a heart attack victim while fending off a woman who's wielding a meat cleaver. In addition, Doc tries to minister to a chronic old drunk and a teenaged girl who attempts suicide in her bathtub. Meanwhile, Faith secretly undergoes a procedure to determine if the lump in her breast is cancerous, leaving an unsuspecting Bosco assigned to a nervous rookie cop; Kim reluctantly consults a lawyer about Jimmy's intention to claim custody of Joey.

Alex wants Ty to keep their relationship quiet. When Carlos almost walks in on them, he's so shocked and happy that Ty is straight that he doesn't realize that the girl is Alex. Carlos lets Ty know that Jason Christopher is the one who told him that Ty was gay.

Faith finishes her radiation treatments and is in pretty bad shape. but doesn't take Dr. Case's advice to take some time off. When everyone notices how sick she looks at the beginning of the tour, she lies and tells them that she caught a bug from her kids.

Later, Sully and Ty are called to rescue a family that has been shot and left for dead in the river. When they arrive at the scene, the father, Jared McKinley, tells them that they were abducted, robbed, driven to the river and shot. Hoping to locate some witnesses, Sully and Ty run a check on the license plates of the cars parked along the river and find that one of the cars was registered to McKinley, which makes him their prime suspect in the shootings.

Doc visits Ryan, who's now walking during his physical therapy sessions.

Carlos decides to take a ride on the fire pole and falls, losing consciousness. Doc, Kim and Alex bring him to the ER where he is finally awake and combative. Dr. Thomas admits him to the hospital for observation because of his head lac and LOC. The nursing staff settles a score with Carlos by putting him in a room with Rodger, a drunk he brought in the day before. Rodger is alternating between screaming, crying, whimpering and non-stop talking -- all at the top of his lungs. He's going through the DTs and can't be sedated, because he admits to being drunk since 1987.

During the investigation of the gang shootout, the officers are questioned and presented with evidence which suggests that Ross was killed by friendly fire; Carlos learns that Vangie is dead and that he might be 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.

Rescuers find the body of Alex's father, and he is given a hero's burial; Faith and Bosco tail a convicted rapist released on appeal, certain that he will rape again; dissatisfied by Tatiana's explanation of her whereabouts the eight weeks she was missing, Sully investigates further and uncovers some astonishing and heartbreaking facts about his wife; after Chevchenko threatens to kill him if he doesn't roll over on Faith and Sully, Frankie tells Swersky that the raid on Chevchenko's numbers business was a hummer bust, leading Chevchenko to threaten a lawsuit and have another angry confrontation with Sully.

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

Doherty, riding on his motorcycle, is first to arrive at a multivehicle collision; Taylor is hit by a car; Tatiana goes to see Chevchenko, and tragedy ensues.

When a fire breaks out in the supermarket where Bosco and his mother Rose are doing some late night shopping, Bosco rescues most of the shoppers but cannot save a young mother when she goes back inside to retrieve her purse. After Jimmy tells him that the fire was probably deliberately set, Bosco is convinced that he saw the arsonist in the crowd outside after the fire. Sgt. Cruz gets Bosco and Faith assigned to the Anti-Crime Unit for a few days so that they can track the guy down. At the scene of another supermarket fire the next night, Faith takes down license plate numbers, Cruz photographs the crowd and cars at the scene, and Bosco nabs the man he saw in the crowd the night before. The man turns out to be a fire buff, but Faith and Cruz's work bears fruit and they find their arsonist -- the son of Doug Maple, an NYFD arson investigator. A depressed Sully is still on leave, drinking too much, and sleeping on the couch at Ty's and Carlos' apartment; Doc connects with an attractive

Doc supervises a new paramedic on her first day; Carlos is arrested after a teenaged patient accuses him of molesting her; Bosco and Faith search for an escaped prisoner; Sully and Davis team up with fire and EMS to save construction workers when their scaffold collapses; in the aftermath of the bank robbery, Faith is troubled when Emily asks her how many people she's killed in the line of duty.

Ty bails Carlos out and unsuccessfully tries to help him smooth things over with Nicole; after Bosco and Faith break up a domestic disturbance between an old friend of Faith's and her lover, Faith convinces her friend to leave the abusive relationship; Alex gets irritated when the other firefighters make fun of her brother; Sully continues to drink and have a poor attitude on the job; Jimmy is appalled when his face appears on a poster for an erectile dysfunction product, and is stunned when he discovers that the company paid the charity for whom he posed for the picture $10,000 for the right to use the picture, and that their website got 3,000 hits the first day from women wanting to know his name; when he discovers that everyone thinks that he's guilty and he's likely to lose his case, Carlos resigns in the hope that Nicole will drop the matter, and he'll be able to avoid a conviction that will end his visits with Kylie and his hopes of becoming a doctor.

Sully's stopped drinking, but his poor attitude remains; Carlos gives his two week notice; a blizzard blankets the city and the squads are called in early; an understaffed Doc defies orders and puts Carlos back on the street as the squads are kept busy rescuing victims of the storm; Faith's initial wariness about Emily's new boyfriend Eric turns out to be well-founded when he is brought into Mercy after an overdose of Special K, but doesn't remember where he left Emily after she also got high; Faith, Bosco, Sully, Ty, Doc and Carlos go out to search for Emily, and rush her to Mercy after she's found in critical condition; Faith and Fred blame each other for letting Emily go out with Eric.

As she keeps vigil by Emily's bedside, Faith recalls her first days at the Police Academy and the beginning of her friendship with Bosco; the fire squad rescues Bosco, Maritza, and a very pregnant Linda Barnes from the inferno, but Lettie Cruz succumbs to her drug binge before they can reach her; Emily is released from the hospital and takes responsibility for her overdose; Bosco tracks down Gary Barnes with Linda's help; Maritza and Bosco's relationship goes to a new level when he attempts to comfort her on the lost of her sister; Kim finally testifies before the review board and stands up for Carlos.

Faith rebuffs Bosco's attempt to apologize for lying to her; the fire squad extricates a driver impaled after crashing into a store; after Doc makes an impassioned defense of Carlos before the review board, a re-energized Carlos goes back out on the street; Sully's job performance continues to decline as he neglects to keep an eye on a woman he was supposed to be guarding, and she snatches her critically ill baby from Mercy's E.R.; after they discover that the woman is mentally ill, Ty takes a multi-story tumble while trying to prevent her from jumping off a roof with the baby; Faith is stunned when an initially reluctant Emily is eager to continue visiting a drug counselor; Ty catches Sully drinking in the R.M.P. and seeks advice from a union rep; Carlos loses his job as part of the department's settlement with the West family.

Sully is sober and back on the job; Faith continues to keep a close watch on Emily; a mutual attraction springs up between Kim and a reporter; Faith and Bosco pursue a man after he steals a bag of money from an overturned armored car involved in a fatal accident; Faith is unable to dissuade Bosco from wanting to hide the cash after the robber drops it, rather than carrying such a heavy load during a foot chase, and is proved right when they return later to retrieve the bag and find that it's been stolen yet again; faced with disciplinary action and investigations by the Major Case Squad and IAB, they pound the pavement trying to find the second perp and discover that the accident with the armored car had been staged by one of the guards and his girlfriend; Maritza ends up stealing the first perp's collar from Faith, which further erodes their relationship; Bosco is jealous when the Major Case Squad detective running the investigation turns out to be Maritza's former boyfriend; as Doc and Kim rush Nicole West to Mercy after a suicide attempt, she tells Kim that her stepfather Anthony has been molesting her; when Nicole's mother refuses to believe that her husband has done anything wrong, Kim implores Melinda to see that her daughter is crying out for help with repeated suicide attempts; after Nicole convinces Melinda that Anthony is guilty and reveals that her accusations against Carlos were false, Melinda apologizes and withdraws her complaint against Carlos and the city; still at odds over trust and honesty issues, Faith and Bosco trade painfully honest barbs and decide to split up; Carlos is elated when Ty tells him he's being reinstated.

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.

Maritza's reckless pursuit of Buford triggers a horrific car accident that leads to multiple injuries to motorists, and triggers an explosion that severely injures Lt. Johnson and kills Alex Taylor; Doc and Kim get to the top of the promotion list; Maritza hangs Bosco and Nunez out to dry over the murder Noble committed; Doc's overwhelming guilt and grief over Alex's death leads him to a career decision; Maritza discovers that Faith has agreed to help Bosco clear Nunez by getting Noble's gun, and goes to Noble's place to intercept her, followed by Bosco and Noble; when Bosco insists on arresting Noble and Faith refuses to turn over the gun, Maritza draws on Faith, Bosco and Faith draw on Maritza, and three shots ring out.

Although Dade encourages him to keep quiet, Bosco tells Swersky everything that transpired with Maritza, Noble, the death of Willie G, and the shootout in Noble's hotel room, and confesses that he killed Noble after Noble pulled out a gun, Faith was shot by Maritza, and that he grazed Maritza's head with a bullet to keep her from killing Faith; wracked with grief that his wife has a bullet next to her spine, Fred attacks Bosco and threatens to kill him when he discovers that Faith became injured while she was helping her partner out of yet another jam; a critically injured Lt. Johnson, in excruciating pain and with only hours to live, begs Jimmy and Doc to ease his suffering; overwhelmed at the sight of Lt. Johnson's wife lashing out in heartbreak and anger, and her husband's horrific suffering and imminent death, Doc sadly helps out his boss one last time; Swersky has Maritza arrested when she refuses to tell him what happened during the shootout; Bosco learns that Noble was working f