<P> Back at the hotel, Mary panics during sex when she notices Anthony's marriage - ring mark and asks who he really is . She forces Anthony to drive her home; the two get into a fight in the car which results in a high - speed crash and the car being totaled, the passengers presumably both dead . </P> <P> The next day, Adam dresses in Anthony's clothes and opens the confidential letter received earlier from the agency and finds the underground - club key, given only to select members . Helen gets out of the shower and tells him to call his mother, then enters the bedroom . Adam asks Helen if she is doing anything that night and tells her that he's going out, but she doesn't respond . As he enters the bedroom, he beholds instead of Helen the now room - sized tarantula cowered against the rear wall . Adam, with a resigned look, sighs . </P> <Ul> <Li> Jake Gyllenhaal as Adam Bell / Anthony Claire </Li> <Li> Mélanie Laurent as Mary </Li> <Li> Sarah Gadon as Helen Claire </Li> <Li> Isabella Rossellini as Mother </Li> <Li> Kedar Brown as a security guard </Li> <Li> Darryl Dinn as the video store clerk </Li> <Li> Joshua Peace as Carl, Adam's colleague </Li> <Li> Tim Post as Anthony's concierge </Li> <Li> Misha Highstead, Megan Mane, Alexis Uiga as the Ladies in the Dark Room </Li> <Li> Jane Moffat as Eve (uncredited) </Li> <Li> Stephen R. Hart as Bouncer (uncredited) </Li> </Ul> <Li> Jake Gyllenhaal as Adam Bell / Anthony Claire </Li>

What is the plot of the movie enemy