Denis Leary Denis Leary

As FX's firefighter drama Rescue Me begins its final season Wednesday (10/9c), it must contend with the question that has loomed over the series like a black cloud of smoke since Episode 1: Will there come a day when reckless hero Tommy Gavin won't come out of a burning building alive?

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Of course, fire isn't his only vice. Although Tommy (Denis Leary

) survived the rescue effort on 9/11, his battle with alcohol and his revolving door of women have put him a number of situations that were just as life-threatening as running into the World Trade Center. So, after six years of ghosts, sex and gallons of booze, is there any chance Tommy escapes the series with a pulse?"Obviously, you want to make sure it's a satisfying end of the journey for the viewers," co-creator and executive producer Peter Tolan tells "I think more than anything we just want to end on a positive, hopeful note. After so many years of 'What the hell is going to happen to this guy?' I think that's the choice we had to make — to offer some glimmer of hope that Tommy might pull it together finally in the end."Standing in the way of Tommy's happy ending, however, is a new type of ghost. Although he's always been haunted by visions of dead loved ones when the whiskey starts to flow, this season his godson Damian ((Michael Zegen), who was paralyzed after an on-the-job accident last season, is a constant, living reminder of his guilt.

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"He's been haunted by the people he couldn't save, and he carries those people around on his back wherever he goes. And in a way Damian is no different than that," Tolan says. "There's just more guilt there. I think that forces Tommy into a different place as a caregiver and a supporter for Sheila."Meanwhile, Sheila (Callie Thorne), who has perhaps finally found peace, forms a bond with Tommy's pregnant wife, Janet (Andrea Roth). The two have put their warring ways aside and are now double trouble for Tommy, who is often reduced to being their errand boy.

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Looking for a reason to escape the house, Tommy has another chance run-in with Kelly (guest-star Maura Tierney) the pot-smoking woman Tommy bonded with after her apartment caught fire in Season 5. When they meet again, however, Kelly is in the final stages of cancer treatment, something Tierney went through in real life just months before filming her return appearance."It was just incredibly brave," Tolan says of Tierney's bold performance. "I don't know how she got her head into the space to actually do that. [Maura] really steered that ship in terms of what that story was and how it ended up on  the screen."Despite surviving the disease, Kelly is furious at the world, which is something to which Tommy relates, Tolan says. "It's about survival and anger — it is anger at survival," Tolan says of the new story line. "And that fits right into Tommy's, 'Why did I have to experience what I've experienced? Wouldn't it have been easier to just die than to go forward in fear?' I don't think Maura feels like she's got anything hanging over her head, but Tommy does, and that may be the difference between the two of them."

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As always with Rescue Me, these weightier issues are undercut with humor. Garrity (Steven Pasquale) is dating a new hottie, but she gets horrendously gassy after sex. Mike (Michael Lombardi) takes a major role in planning Colleen (Natalie Distler) and Black Shawn's (Larenz Tate) wedding. And all of the guys of 62 Truck hilariously take parts of Lou's (John Scurti) physical so he can get an otherwise-unattainable clean bill of health."It's just typical Rescue Me," Tolan says with a laugh. "As sad as it gets, that's how f------ off the wall it gets with the comedy."And will Tommy be laughing when it's all said and done? "You don't want to send out a message that says human beings don't survive tragedy, because the reality is that they do," Tolan says. "We [looked at 9/11] with big laughs, and then you realize that laughter is the whole coping mechanism. The show was saying, on some level, 'Look: We go on, we laugh, we survive.'"Rescue Me airs Wednesdays at 10/9c on FX.