The film opens with Elizabeth, a new bride, being brought home by her husband Henry on their wedding day. The home is palatial and staffed only by two workers, the enigmatic Claire and blind Oliver, who view her as a curiosity. Elizabeth's life is initially idyllic and Henry tells her that she can enter any room save one, located in the basement, before leaving for work. Initially entertained by clothing, jewellery, and the house's luxuries, Elizabeth's curiosity gets the better of her and she explores the forbidden room, where she discovers clones of herself. When Henry returns home he quickly surmises her deceit and murders Elizabeth. One of the clones is awoken and goes through the same experiences, differing in that she is successful in defending herself against Henry, resulting in his death. Her deceit is quickly discovered by Oliver and Claire, the latter of whom immediately suffers a heart attack and is whisked away to the hospital. Left alone with Elizabeth, Oliver blackmails her into staying by claiming that she would be quickly arrested for Henry's murder if she left and that he can only protect her if she remains. Oliver even goes as far as murdering a police officer and friend of Henry's that comes to investigate a call for help Elizabeth had made the night before, which the two claim was instead made by Claire. Aware that Henry has been creating clones but wanting to know the full truth of what went on in the house, Oliver imprisons Elizabeth in a room and forces her to read Claire's diary. Through this it's revealed that Claire and Henry were brilliant scientists who sought to clone Henry's dead wife Elizabeth. The initial attempts at cloning are unsuccessful, as the first clone is unable to remember anything and dies by what Henry claims is an accidental suffocation during her sleep. Eventually the cloning is met with limited success as the Elizabeth clones are able to retain some of the original Elizabeth's memories during the cloning process but are