Tommy copes with a tragedy. Jerry must decide what to do when his wife's condition worsens. Sean has a crisis of faith. Lou learns some shocking facts about Candy. And the crew responds to a multi-level building fire with people trapped inside.

In the aftermath of the fire, the members of 62 truck struggle to pick up the pieces and look towards the future. Down at The Rock, the new probies receive a familiar speech and stand before a new leader.

Tommy's sister suddenly shows up in town when their dad is about to inherit a million dollars. Tommy and Janet decide to renew their wedding vows. Meanwhile, Mike is worried when he finds a lump.

Tommy and Janet are brought together once again by another Gavin family tragedy. Jerry ends up not showing up for work. Mike decides it is time to look for some advice about his sexuality. Meanwhile, Maggie has a surprise for Sean.

Janet decides to meet with Tommy after not speaking with him for months since the sudden death of their son. Uncle Teddy refuses to allow anyone to help him get out prison. Tommy is shocked when he accidentally discovers just who his nephew has been sleeping with.

The hockey game rematch between the NYPD and the FDNY is right around the corner and Tommy must figure out a plan to save himself from being pummeled by the cops who have it out for him. Tommy's relationship with Sheila is discovered by the guys and they must adhere to tradition to handle it in their own way. When Tommy is visited by his demons during a fire, Franco comes to his aid... with devastating results.

When Tommy, Johnny, and Mickey confront Father Murphy it results in tragedy. Sheila needs Tommy's help with a domestic issue. Jerry decides it's time to get a nurse to care for Jeanie. Lou offers to help Candy out with her situation. And Laura discovers the truth behind Franco's poetry.

During a night out, Franco and Tommy meet two women. Tommy is finding himself bribing his daughter Colleen before she tells their mother about his indulgent treatment of her sister Katy. Jerry visits his wife Jeannie in her expensive nursing home and soon goes to Lou for financial help. Meanwhile John Sr. insists on having his 83rd birthday at a restaurant that no one else likes.

Jerry forces the crew to attend a birthday party that his son is throwing for his boyfriend. Meanwhile, Tommy makes a move on Mariel after she tells him she might not be his half sister after all. Franco asks Laura to move in with him while Sheila tries to make Tommy jealous by showing off her new girlfriend.

Uncle Teddy appears surprisingly stoic after a staggering personal loss, but finally bursts at the seams and has the gang cornered. Janet and Sheila's plan goes haywire and leaves a trail of destruction in its wake.

New York City firefighter, Tommy Gavin, cannot escape the ghosts of those who have died around him as he faces the everyday challenge of saving lives while trying to fix his own.

Tommy has a chance at finding his kids with help from his oldest daughter. Chief Jerry asks his son for help when his wife's condition worsens.

Tommy ends up promising Janet that he will help her with the baby, but neglects to tell her about his future plans with Sheila. Meanwhile, Franco decides to check up on his daughter, Keela.

John Sr. ends up disappearing after arguing with Tommy about their living conditions. Tommy is none too thrilled with Lou's latest love interest, while Jerry's new woman might prove to be dangerous for him. Also, Sean and Maggie meet with the priest to discuss their upcoming wedding.

A "friendly" date between Tommy and the widow of his dead cousin takes a unexpected turn when she makes a move on Tommy. Franco's ex-girlfriend shows up at the firehouse and claims he's the father of her five-year-old daughter, turning his life upside down.

Tommy comes to terms with the reality of his broken family as a result of a shocking experience with his father. When a freak accident occurs, Franco must make a life-changing decision, and Chief Reilly is forced to expose a family secret in order to save his career.

Tommy attempts to handle the insanity of his father while defending Colleen's new lifestyle to Janet. At the firehouse, Sean and Mike the Probie unknowingly launch a full blown wager among the crew.

When Janet needs more money to cover house repairs, Tommy turns to Uncle Teddy and his "little" friend to help him out with extra cash. When Franco's father has a stroke, Franco finds himself trying to juggle work and raising his daughter on his own. Meanwhile, a goodwill tribute to the firefighters lost in 9/11 goes awry and the firehouse is put in jeopardy.

Tommy asks his cousin for help in understanding the bizarre visions he's been having. The crew tries to help Laura understand the essence of male comaraderie.

Tommy seeks the truth about Sheila while trying to get his kids back; Lou does not like the person he has saved through a bone marrow donation; Franco's addiction puts those he loves at risk; Sean's new girlfriend habitually dates firemen.

After a game of street hockey, Sean takes some sleeping pills believing they are painkillers and it has an unwanted consequence. In the meantime, Tommy and Angie decide to go on their fake date that they know will upset Janet. After having a close call, Lou gets a new angle on firefighting from his Uncle Red.

The crew faces more than accustomed when rescuing a man from his burning apartment; Sean has a request for Maggie's dad; Franco thinks his new girlfriend is hiding something from him; and Tommy realizes that his crew's future together may be in jeopardy.

Following a meeting with Janet, Tommy has yet another confrontation with Johnny; Teddy's conjugal visits with Ellie prove to be a letdown; and Franco tries to befriend his new girlfriend's mentally challenged brother. Elsewhere, Tommy keeps his vigil at Stack's bedside.

Janet has given birth to a baby boy---whom she fears prefers Tommy to her. But Tommy has a bigger problem: He's suspected of starting the beach-house fire. Meanwhile, Jerry's son asks him to be his best man at his commitment ceremony; Richie wants Franco to marry Natalie; Lou and Theresa get distracted in church; and the volunteer firefighter (Jennifer Esposito) who rescued Tommy from the beach house takes an interest in him---and isn't shy about letting him know.

Tommy copes with the loss of his father and a new man in Janet's life. Sheila finds a different way to deal with her issues while Sean, Franco, and Mike concoct a surefire way to get rich and laid.