There are few surprises in Monster, a dark, harrowing film about an ill-fated lesbian relationship that doesn't just ruin the lives of the two women involved, but of many others, too.

Written and directed by Patty Jenkins and based on a true story, Monster chronicles the last few years in the life of real-life prostitute-turned-serial killer Aileen Wuornos (Charlize Theron) and her relationship with a younger woman, Selby (Christina Ricci).

The love affair between Aileen and Selby begins by accident when Wuornos wanders out of a stormy night into a gay bar to spend her last five bucks on beer. She knows no one in the gay bar and behaves more like a frightened animal than the seasoned alcoholic she is. The bartender, sensing trouble, is reluctant to serve her, and she is rudely reminded it’s a gay bar.

The only person who behaves decently toward her is Selby, who offers to buy her a drink. Wuornos snaps at her at first, believing every act of decency comes with a price (usually a sexual favor), but as the night progresses, the two develop a rapport fueled by alcohol. Wuornos makes it clear she’s not gay but she gradually loses her fear of Selby and ends up crashing with her for the night. Though their early encounters are platonic, a bond forms which eventually turns into a stormy, co-dependent relationship.

It is clear from the beginning that Selby really wants a girlfriend; if Wuornos is physically homeless, Selby is emotionally so, and equally lost in the world. Temporarily living with her parent’s friends in Florida because her parents suspect she’s a lesbian, and unable to work because of an arm injury, Selby doesn’t seem to have any long term plans or dreams--which makes her a perfect candidate for Wuornos’ drifting, smooth talk and promises of a cozy future together.

This future never materializes. The pair repeatedly run out of money, which sends Wuornos back to hooking and worse. Predictably, not long after the couple’s first kiss, things quickly take a turn for the worse: Wuornos is horribly raped by a john and kills him in self-defense. Although it is painfully obvious that Wuornos’ psyche is already beyond the reach of common decency before she even meets Selby, this experience seems to push her over the edge. She temporarily attempts to find a “normal” job but fails miserably, and soon she returns to hooking and murder, with her motives becoming murkier and murkier over time.

While watching this unfold, I wanted to be someplace else. The downward trajectory is immediately established in the film, and other than brief scenes of affection between the two women, there is little relief from the relentless violence and despair.

By all reports, in real life Wuornos' childhood itself was the stuff of horror stories: she was a victim of much violent sexual, physical and psychological abuse throughout her life. The press, of course, glossed over this in their rush to loudly proclaim Wuornos the nation’s first female serial killer. During her trial, she showed many signs of psychosis and insanity, but was allowed to stand trial and was subsequently found guilty and executed in 2002.

Over time, Wuornos has also become known as the lesbian serial killer, despite the fact that she’d slept with hundreds of men, had boyfriends, and clearly doesn't identify as gay--because it's easier for the press to just describe her as a "lesbian" than as a straight woman who ended up in a relationship with another woman simply out of an overwhelming need to be loved. Jenkins does go to great pains to make this distinction clear in the movie, but it is still unlikely that most in the audience will understand or remember the difference when American culture so quickly and frequently labels anyone in a relationship with another woman a lesbian.

In the midst of such a bleak subject matter, the film does showcase uniformly terrific acting. Charlize Theron has generated well-deserved critical buzz over her transformation into Aileen Wuornos; unless you’re a serious Theron fan you may not even know it's her, she’s admittedly that good. Christina Ricci as Selby has never looked more radiant: Selby wears her vulnerability and youth on her sleeve.

The story is assuredly told, and the filmmakers do find a thematic groove when they contrast Wuornos’ hardcore cynicism with Selby’s diminishing optimism. But by setting Wuornos up as a lost cause from the start and Selby as the naïf who falls for her, there little about this film that hides the fact it is yet another bleak look at a doomed romance between two women.