Yet, the two see kindred spirits in each other and soon enter into a passionate lesbian affair. That doesn't sit well with Donna, prompting Selby to move out and into a motel room with Aileen. The latter, believing she's finally found love, decides to quit hooking and get a legitimate job. When that doesn't pan out and the two realize they need money to survive, Aileen returns to her old profession.

When one such "job" turns horribly bad, however, Aileen ends up killing the "john." With a newfound taste for blood and the desire to make a better life for herself and Selby, Aileen ends up going on a killing spree that eventually draws the attention of the police and threatens to ruin her happiness and relationship with her new lover.

Accordingly, some actresses - perhaps sensing Father Time and Mother Nature collectively conspiring against them - decide to take matters into their own hands before their beauty and allure for roles wanes. Following in the footsteps of Halle Berry in "Monster's Ball" and Nicole Kidman in "The Hours," the gorgeous Charlize Theron ("The Italian Job," "Trapped") has opted to downplay her beauty to win and play the lead part in "Monster."

Based on the real-life story of Aileen Wuornos, a Florida prostitute who was executed in 2002 for committing multiple murders, the film features Theron in a decidedly less glamorous, unflattering and nearly unrecognizable role. It's arguably her best work and a near shoo-in come award season time. As I'm not familiar with the real woman, I can't attest to the visual accuracy of the portrayal, but Theron is certainly convincing in the part.

The problem, however, is that her disappearance into the character is nearly so complete and believable that it actually becomes a bit of a distraction. At times, one can help but try to find the once radiant actress under all of the makeup, prosthetic teeth and reported weight gain. As a result, viewers may end up ignoring some of what's occurring while starring at the shockingly altered beauty.

It's an unavoidable but certainly not debilitating fault that thankfully dissipates the further one travels down this intriguing but sad tale. With occasional voice-over narration by Theron, the story follows her destitute and emotionally desolate character who finally finds a bright spot in her otherwise dim and dismal life.

It comes in the form of the lesbian character played by Christina Ricci ("Anything Else," "Pumpkin") who sees something in Aileen - perhaps a kindred outcast spirit - that no one else has noticed. The two quickly become lovers, but their need for cash obligates Theron's character to continue prostituting herself. One such encounter turns ugly and then murderous, thus leading to the eventual murder spree that got Wuornos caught, convicted and ultimately executed.

Not being up on the true story, I have no idea if writer/director Patty Jenkins (making her feature debut) has taken some or a great deal of artistic license with the facts or characters. Whatever the case, the story is intriguing and surprisingly heartbreaking as we watch the characters' desire for something good in their lives get trampled upon by others, society in general, and their own actions.

Of course, some viewers won't feel that way at all. They'll be repelled by who the characters are and what they do, and will likely think they all got what was coming to them. Others, however, will see the human qualities that Theron and Ricci bring to their characters that make them engaging. That doesn't necessarily mean that they're likable or defensible. Rather, they're simply sympathetic since one can't help but feel bad regarding the cesspool in which these young women are treading but inexorably sinking.

While some of that stems from her character's voice over narration, most can be attributed to Theron's stunning performance. Notwithstanding the physical side of it, the actress delivers a tour de force acting job that should open those previously locked doors to better roles. Ricci, as usual, plays yet another on the edge character and nails the part.

Although there are a handful of supporting characters - Bruce Dern ("The Glass House," "The Haunting") plays a Vietnam vet who sees a kindred and misunderstood spirit in Aileen, while Annie Corley ("21 Grams," "Seabiscuit") plays Selby's "foster mom" who doesn't approve of her hooker friend - this is really just a two character show and the lead actresses are simply terrific in the parts.

Shocking, disturbing and much more, this film obviously isn't for all viewers. Yet, for those who give it time to unfold - and can get past trying to find Theron's hidden beauty - it's an intriguing, engaging and even moving look at those who crawl along the underbelly of life. "Monster" rates as a 7 out of 10.