You've probably heard something about the story by now: In early 2001 a German man was arrested for killing, disemboweling, cooking and eating another man. What makes this story particularly (ok, especially) bizarre is that the victim was a willing participant in the event! He actually wanted to be eaten! Obviously a story like this is entirely ripe for a movie adaptation, which is where Martin Weisz' Grimm Love (aka Rohtenburg or Butterfly: A Grimm Love Story) comes in. (Another film covering the exact same story, Marian Dara's Cannibal, is presently available on video. It's a lot more graphic, but not quite as engaging as Grimm Love.)
"Based on actual events," but using a fictional character for a framing story, Grimm Love focuses on American graduate student Katie Armstrong (Keri Russell), a committed researcher who finds herself absolutely obsessed with the story of flesh-eater Oliver Hartwin (Thomas Kretschmann), a rather sick man who's doing jail time for dining on his fellow man.
Given that we only know a few small snippets about Hartwin's life, Weisz cleverly juxtaposes Armstrong's story with early details from Hartwin's life. As Katie gets the sketchier stories about the killer's childhood, we're offered the anecdotes in flashback form, and as she gets a whole lot closer to the seriously slimy truth, the b-story material gets decidedly more ... icky. The whole (and admittedly languid) affair comes to a head with a powerfully compelling two-headed sequence: Katie gets to see the carnage on videotape as we switch back and forth to Hartwin's final descent. And it ain't pretty.