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.

A devastating fire has a profound effect on the crew; Tommy wrestles with his feelings about the baby; Alicia (Susan Sarandon) returns with a proposition for Franco; Troy breaks up with Sheila while Lou makes a tough decision about Theresa; and Sean apologizes to Mike about the fire he set that burned down Mike's mother's house.

Janet plots revenge when she learns what Tommy did with the baby; Franco questions his marriage proposal to Natalie in light of Alicia and Keela's return; and Tommy faces his ghosts.

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.

An exotic visitor sparks mixed reactions in the firehouse. Tommy deals with the possibility of expulsion from the FDNY and a new sponsorship role in AA. As Mike and the guys renovate their new bar, Sheila learns that being a big sister isn't always easy.

The calls from Tommy's AA sponsee increase as Tommy attempts to navigate a touchy issue with Colleen. Genvieve's interviews spark controversial viewpoints in the firehouse concerning the political and religious implications of 9/11-viewpoints which Mike will not tolerate.

Tommy makes a shocking discovery regarding Jimmy's whereabouts on 9/11. Sheila takes drastic measures to purge the negative energy from her life as Sean's back pain gets worse. The bar, however, finally takes a turn for the best as the guys enjoy a fruitful opening night.

After a run in with Janet's brash new boyfriend, Tommy grows concerned about Katie's whereabouts. Sheila is finally able to come to terms with Jimmy's death as Damien makes the decision to follow in his father's footsteps.

A personal milestone finds Tommy back at Ground Zero. Genevieve's perspective on 9/11 incenses Tommy, whereas Franco's point of view has more dire consequences. Meanwhile, Sean's back pain turns out to be more serious than he had expected and the success of Mike's bar becomes a handful.

Tommy and Janet attempt to survive a weekend together at Katy's new prep school. Meanwhile, Lou sees Tommy's absence as a way to move in on Genevieve. Teddy and Maggie receive vulgar propositions and Sean's stomach pain acts up at an inopportune moment.

A late-night cleanup turns into a nightmare for Tommy when several unexpected visitors stop by the bar. Feinberg allows Damien to ride along with the crew, but may not be prepared for the consequences.

Tension runs high as Needles holds the guys accountable for their lack of judgment. Tommy steps up and takes responsibility for Damian's future in the firehouse. Sheila provides Tommy with an oasis as a sign of her gratitude but it may not be enough to save him from the wrath of Mike, Dwight, and the ghosts of Tommy's past.

Tommy and Mike must find a way to mend their fences at work; Sheila tries to get Tommy to control his drinking with her leverage; Lou must relive an unpleasant memory; Franco heads back to the boxing ring; and Sean has his heart-to-heart talk with his mother.

Though Tommy's pacts with Sheila and Janet have begun to unravel, there is one Gavin who remains sexually adventurous much to Tommy's chagrin. Garrity divulges his medical secret, Tommy proclaims he's been drinking at AA, but its Mickey who will offer the final surprise.

The guys visit Sean in the hospital; Katy is home from school and wants a family dinner---one that includes Colleen and Black Shawn; and Lou and Tommy make a wager concerning the women in their lives.

After dealing with a particularly horrific accident on the job, Tommy questions his feelings in a dream sequence with his dead father, brother and son, and Jimmy Keefe. Meanwhile, Sean has an unwanted visitor at the hospital; and Lou has a very-much-wanted visitor to his apartment.

Franco has his first FDNY-tournament fight, and he and Carla (Tawny Cypress) have an encounter outside the gym; Candy cooks dinner for Lou; the guys have a surprise for Sean when they visit him in the hospital, and he has one for them. The guys also plan an outing for the kids in the cancer ward.

As Damien joins 62 Truck, Sheila reminds Tommy of his promise to watch out for him. Meanwhile, Janet gives Tommy guidelines for their relationship; the guys attend a memorial dedication for a firefighter who died on 9/11; and Sean is released from the hospital, vowing to live life "to the fullest."

An outburst lands Tommy cleaning duty as a mysterious woman strolls through the firehouse; the Gavins confront Tommy about his alcoholism, but their plan does not unfold as expected.

The perfect party becomes a nightmare when a herd of brutish women infiltrate the bar. Tommy's love triangle reaches new heights.

A no-nonsense woman, looking for a date, shows up at the firehouse talking trash; Janet offers Tommy an ultimatum; Needles and Lou concoct a battle of the sexes; Sean's medical condition moves lower on his body.

Damian receives an offer that unsettles Tommy; Lou discusses his upcoming wedding plans with Tommy and Needles.

Tommy has rocky encounters with Janet and Sheila, and an encounter with Kelly that isn't as rocky. Meanwhile, the guys go grocery shopping with the newly domesticated Lou.

Franco steps into the ring with one of Carla's friends;Tommy tends bar after a failed rescue leaves the crew in the dumps.

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.

A terrifying vision of the afterlife leaves Tommy shaken as he attempts to reconnect with his friends and family back on the outside. At the firehouse, the crew’s fate hangs in the balance when the department decides to cut costs.

Tommy comes to terms with his nightmare and tries to do right by those around him, but his plans fall by the wayside when the gang gathers at the bar post save.

Tommy's first day back on the job is a busy one as the crew races from call to call. By the end of the shift, the guys are all exhausted, but it's Lou who feels it the most.

With the cookout quickly approaching, the guys hatch a plan to sneak Lou out of the hospital. Sean and Mike attempt to do good, Teddy bonds with Colleen, and Father Phil gives Tommy a piece of advice that sends him reeling.

A night of heavy drinking turns ugly when Tommy blacks out and loses control. The next day, the crew struggles to put the pieces together as they search for the whereabouts of Colleen.

Tommy loses his nerve when a young driver's recklessness reminds him of his daughter's new lifestyle. After a meeting fails to put Colleen on the wagon, Tommy is forced to pursue a more aggressive method to get her life back on track.

When headquarters shuts down the house, the crew formulates a makeshift response to a nearby call. A face from the past stirs Tommy and Janet's emotions as their date begins to unravel.

Needles' political leverage catches HQ off guard, leaving them no choice but to reopen the house. Feinberg loses control, Damian saves a helpless victim, and Tommy and Sheila find themselves in hot water.

Tommy and Sheila find themselves in hot water with Janet and Mickey and realize the truth about their own relationship. Damian attempts to leave the crew, but is seduced back by the camaraderie of the brotherhood.

Tommy and Sheila do their best to adjust to life after Damian’s accident. Sheila copes with her grief, Tommy struggles to budget his time, and the guys find themselves with a new pickup ploy.

With Damian confined to a chair and a new baby on the way, Sheila and Janet join forces and shake-up Tommy’s family life.

The guys go stir crazy waiting to catch a job. Lou fakes his physical, a news team memorializes Jimmy, and Tommy is saved by an unfamiliar face.

Tommy swoops into action, putting an end to Kelly's dull date and to his spell of uselessness. Lou becomes godfather, Colleen finds a dress, and Tommy sits down for his interview.

What starts as a controlled interview takes a turn for the worse, ending in a full-on brawl. The beef continues even after the guys survive a harrowing scenario at a call.

Tommy has his badge revoked when his latest tirade goes national. But Sheila’s two-pronged attack hits Tommy’s critics where they least expect it, vindicating Tommy and clearing the Gavin family name.

A day at ground zero inspires Tommy to write letters to his loved ones. When Lou betrays his trust, Tommy returns to ground zero with an old friend.

Franco demands a sense of responsibility around the house, but a precarious call puts his leadership skills to the test. Lou delivers Tommy's letters unbeknownst to Tommy.

In the tradition of the Gavin family, Colleen's wedding is an emotional if not debaucherous affair. The high spirits quickly fade, however, when the guys tackle the mother of all fires.

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.