"The Sessions" is based on the true story of Mark O'Brien, a polio victim with an iron lung who, at the age of 38, hired a sex therapist on a personal quest to lose his virginity. The picture won two awards at the 2012 Sundance Film Festival—one for best dramatic film and the other for the ensemble cast—and is a tailor-made talk piece for curious adult audiences. Writer-director Ben Lewin, a former polio sufferer himself, has helmed a sincere, at times lightly funny, drama about the importance of living a full life no matter what obstacles are thrown one's way. In turn, Mark deeply affected a number of friends and acquaintances, many of them female, some of them who loved him but could not see themselves committing to such a fundamentally handicapped man. When he was gone—he passed away in 1999 at the age of 49—he had long made a lasting mark on the world and people he left behind.

With a limited number of locations and few crucial exteriors that couldn't be repurposed for a different setting or medium, "The Sessions" frequently reminds of either a stage play or a cable movie rather than a theatrical feature. There is an unhurried, unassuming quaintness to the story and a concluding send-off with a truthful, if Hallmark-ready, message. Subplots go unexplored, there to fill up time more than anything, from sex therapist Cheryl Cohen-Greene's (Helen Hunt) home life with husband Josh (Adam Arkin) and teenaged son Tony (Jarrod Bailey)—why is Josh so nonchalant about his wife's profession, and does Tony even know what she does?—to Mark's dedicated, no-nonsense attendant Vera (Moon Bloodgood) and her vague flirtations with a motel clerk (James Hiroyuki Liao). Little of this goes anywhere, but there is an authenticity to most of it all the same; it simply would have helped further for writer-director Ben Lewin to explore the other facets of his narrative.

Once seen, it won't be the film as a whole that most viewers will be talking about, but the strength of the performances. This is one case where the acting usurps the bigger picture, and the two leads are virtual sure things for Oscar nominations. When people use the word "transformative" from here on out, they may very well think of John Hawkes, who is portraying someone so diametrically opposite his roles in 2010's "Winter's Bone" and 2011's "Martha Marcy May Marlene" that no one unaware will be able to guess the actors are one and the same. Hawkes never plays Mark as someone to feel pity for; he's a bright and funny guy, a talented poet who beat the odds to graduate from UC Berkeley. He feels plenty of guilt all the same, a man raised Catholic who visits an understanding priest (William H. Macy) about his carnal desires. On top of that, he blames his illness as the catalyst for why his parents weren't there to save his sister from an untimely death. Hawkes' performance is nothing short of exquisite, and he does it all while moving no more than his head. As Cheryl, Helen Hunt (2011's "Soul Surfer") shows no fear sliding into the skin of a woman who makes her living from solving people's sexual hang-ups, dropping her clothes and sliding into bed without batting an eyelash. The difference between herself and a prostitute? "A prostitute wants your return business. I don't." As Mark begins to make his signature imprint on her even when she's not with him, Hunt does a touching job of exhibiting Cheryl's inner turmoil and desire to remain professional. Still, when he dies some ten years later, she remembers him, and can't help but shed a tear at what has been lost. "The Sessions" is uneven and perhaps a little too tidy as it aims to promote one man's extraordinary spirit. It is John Hawkes and Helen Hunt, however, who are most worth seeing.