Two new recruits join the emergency services and work with older, wiser partners. Davis becomes a policeman, like his father, and Carlos a paramedic. Two other Paramedics, Bobby and Kim, find themselves rushing from emergency to emergency. Bosco and Yokas, the other police officers, and Jimmy and his fellow Fireman have their own crisis' to deal with.

Mercy's new E.R. attending gives the cops and paramedics a hard time while ignoring Carlos's attempts to hit on her; Doc is saddened to hear that Jerry has decided to take a disability retirement; Jimmy is upset when Joey goes to Bobby first after he becomes ill as a result of Jimmy's letting him overindulge in sweets; Jimmy and Bobby take out their conflict over Kim and Joey in a game of one-on-one; Sully and Ty arrest a purse snatcher who will do anything to stay in jail once he discovers that his victim's son is a mobster; Faith hands out street justice to a gangbanger responsible for the deaths of two little boys.

On Thanksgiving Day, Bosco tries to resolve a family conflict in a restaurant while Faith deals with the same thing in her own home. Bobby's mother refuses to allow Matty to attend the family's holiday celebrations, and leaves it up to Bobby to tell his brother. After a shooting, Ty and Sully disagree over how they should report the incident to their superiors and the investigating team.

An explosion in a building about to be demolished leaves men trapped inside, forcing the firefighters to make terrible choices; Fred's drinking problem escalates; Doc cancels his date with Brenda.

Ty spends the shift on foot patrol with Candyman and discovers some disturbing facts about both his late father and Candyman; romance blooms between Doc and Morales after Doc's father tells him to get on with his life; Matty's attempts to make amends for past misdeeds have upsetting outcomes; Jimmy has an unexpected and unpleasant visit with his bookie; Faith clashes with the mother of a missing girl; Sully puts in a good word for a hit-and-run driver to a completely unsympathetic D.A.; and Bobby is crushed to learn that Matty was an unwitting accessory to a felony homicide.

It's Valentine's Day and Bobby and Kim have spent the night together; Bobby's confession of love leads Kim to realize that they've made a big mistake; after agonizing all day, she finally confesses and breaks Bobby's heart; seeking solace in a bottle, Bobby finds himself at a local bar next to a woman who has also been jilted that day, and they go off to her place; Fred drunkenly totals the car on the way to pick up Emily and Charlie; Faith arrests him and refuses to bail him out; when he finally arrives home, Faith has his things already packed and throws him out; Carlos tends to a girl who runs into a bus and then falls for him; the gay community is targeted by a gunman and a vigilante group forms to find the killer; Ty arrests a girl for auto theft who turns out to be Malcolm's sister; and Faith lets Bosco know that she is fed up with his bigotry.

As he comes around a corner in pursuit of a gunman, Davis shoots a man who is pointing a gun at Sully, unaware that the man is innocently returning the service revolver which Sully dropped when he fell. Davis's guilt leads him to doubt whether he should remain on the force, until Sully straightens him out. The tension between Bosco and Faith continues to escalate. Both Bobby and Jimmy introduce their new girlfriends to Kim, who isn't thrilled with the potential competition.

Sully lives his worst nightmare as the police search the city for a man who is buried alive and whose kidnappers are involved in a fatal car crash; Kim and Bobby find an abandoned 4 year old boy wandering the streets; Sully's mother wanders off from her nursing home; Carlos adopts a deceased patient's cockatoo.

A rapist attacks three victims; Yokas agonizes over her finances, her marriage and her pregnancy; Bosco's jealousy threatens his relationship with Nicole.

While coping with work demands, a recovering alcholic husband and a disturbing visit with her parents, Yokas confronts her long held beliefs and emotions.

A group of prisoners escape from a delivery truck. Yokas and Fred have another big fight in which she accuses him of drinking again. She tells him that she had an abortion. He wants her to leave the house, this makes her stay over at her parents home. However, by the end of the episode, they are back together, she realises that she can't live without him and that she is sorry for accusing him of still drinking.

Meanwhile, Bosco gets a bunch of flowers from a former lover. He smells the flowers which turn out to be poison Ivy. Bosco and Yokas also have a fight when she tells him that she had an abortion. He accuses her of lying to him and he refuses to speak to her, until she forces him to go the hospital to sort out the poison Ivy problem. She regrets lying to him.

Bosco, Yokas, Sully and Davis search for a cop killer on the streets, and cope with an obnoxious new sergeant at the station house.

Faith's excitement over having her husband to herself for the weekend is dashed when Fred decides to spend the time trying to win a truck; angry, Faith organizes a drunken girls night out, meets a handsome photographer, and ponders an affair and what might have been; Fred outwits his opponents and wins the truck.

Ty, Sully, Bosco, and Faith rush to the scene of a school shooting; Sully and Tatiana ponder their future together; Kim continues to struggle with her depression.

Bosco starts having panic attacks and goes to see a therapist, but it doesn’t work and later he turns to the only person who’ll listen. Carlos is discovering the trials of single parenthood and starts thinking about adoption. Faith is studying for the Sergeant's exam. However, her concerns about Bosco’s mental and emotional health cause her to fail, and this angers Fred, and he storms out of the house. But later, he sees Faith comforting a sobbing and weeping Bosco after Bosco admits that he couldn’t go back to the World Trade Center towers after they fell down.

Hopelessly in love with Kylie and concerned that she will lose her Filipina heritage if she is adopted by a white couple, Carlos considers raising her until he realizes that the couple can give her the sister, the grandparents, and the extended family that he cannot. Kim's preoccupation with her new PDA drives Alex crazy until they are able to use it to save a very sick man, thus redeeming themselves in the eyes of a hypercritical Dr. Peterson. Faith and Fred are still on uneven ground about the Sergeant's exam. In an effort to shake Chevchenko's tree, Faith and Sully execute a clever plan to disrupt the Russian's bookmaking operation which also opens the door to the possibility of the still-missing Tatiana's return. Bosco is cleared for duty, and he and Faith agree to be partners again as soon as he returns.