Apart from that initial scene between Laurie and her tormentor, Michael (aka "The Shape") is played by actor James Jude Courtney. He's the one you'll recognise in that opening prison scene, as well as the majority of the rest of the film.
While he's not a household name, Courtney has appeared in a number of big film and TV projects. He appeared alongside Tom Cruise and Nicole Kidman in Far and Away, starred with Meg Ryan and Andy Garcia in When a Man Loves a Woman, and even had bit parts in Buffy the Vampire Slayer and Babylon 5.
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