Simon James (Jesse Eisenberg) is a timid young man, working for a mysterious government organisation, scratching out an isolated existence in an indifferent world. He is overlooked at work, scorned by his mother, and ignored by the woman of his dreams, copy room girl Hannah (Mia Wasikowska). Undermined wherever he turns it appears his life couldn’t get worse – that is until the sudden arrival of a new co-worker, James Simon. James is both Simon’s exact physical double and his opposite - confident, charismatic and good with women. To Simon’s horror, James slowly starts taking over his life.