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.

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.