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.

Sully and Maggie reconnect; Bobby visits his brother Matty and tries to prepare him for his release from prison; Sunny asks Kim for a place to stay and runs away when Kim refers her to a shelter; Carlos hits a pedestrian with the bus; Faith and Bosco investigate a grave robbery and ponder immortality; Jimmy rescues a new recruit who is trapped under a collapsed ceiling in an apartment fire; Bobby takes Doc's advice and tells Kim how he feels, only to learn that Kim feels she isn't good enough for him; Sunny ODs and Bobby helps a saddened Kim find out her real name and hometown so that her parents can be notified; Sully's approach to ""problem solving"" goes horribly awry in a domestic dispute; Carlos and Doc come to blows over Doc's training methods, forcing Morales to break them up; Sully learns that Ty has good instincts, enabling them to save a teenage girl from a sexual predator.

Faith, Bosco, Sully, Ty and Candyman race through the neighborhood on foot in pursuit of a trio of Uzi-armed thieves; Candyman risks his life to save Ty; Bosco's cold refusal to get medical assistance for one of the perps leads to the robber's death; Ty searches for the truth about his father; Bobby's mother tells the police where to find Matty, who desperately pleads with Bobby to give him some getaway money; Bobby agrees, but begs Matty to turn himself in; Matty gets high and takes off, leaving Bobby crushed and seeking consolation from Kim; and Carlos finds out about Doc and Morales.

Carlos falls behind in his studies and then hears some shocking news from Vangie; the cops search for a two-year old girl missing after her family is involved in a car crash; Bosco and Faith contend with a disabled man dealing drugs to children; Sully and Davis track down the alcoholic who attacked the pastor of Sully's church.

Doc and Carlos are rescued by the firefighters when they get trapped in an eighteenth floor apartment with a patient who cannot walk; Ty comes to the end of his probationary period; Faith discovers that she's pregnant again; the firefighters come under fire from a madman when they arrive to fight a car fire.

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.

A secret threatens to destroy Jimmy's relationships at work and home; Sully makes a date with his pretty neighbor; Bosco gets violent after his mother is beaten by her boyfriend.

Bobby comes to the aid of his old friend Paulie after Paulie's sister begs Bobby to help her brother with his drug addiction, but becomes enraged when Paulie breaks into Bobby's mother's house and robs her to support his habit.

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.

On September 10, 2001, Sully and Ty party in Atlantic City on the eve of Sully's wedding to Tatiana; Faith makes plans to see her doctor for her biopsy results; Jimmy can't get enough rest after nursing a sick Joey the night before; Kim isolates herself and sinks deeper into depression, and Bosco goes looking for love in all the wrong places.

It's September 21, 2001 and the squads continue to battle through their emotions and their misgivings about their hero status, while working double shifts and spending every free moment at ""the pile"" searching for the missing; Kim returns to work and teams up with Doc, which allows an emotionally frayed Alex to return to paramedic duty; an exhausted Sully attempts to co-exist with his prospective in-laws while he waits for an opportunity to marry Tatiana.

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.

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.