"Keep it in the family" takes on a new meaning -- both onscreen and off -- in Andrew Birkin's disturbing Cement Garden. The film stars two members of Birkin's own family, including his son Ned Birkin and his niece Charlotte Gainsbourgh as siblings Jack and Julie. The lack of parental control forces a mutation in the roles of brother and sister, a mutation that becomes the main theme of the tale. The performances of all four leads leaves a sense of repression and secrecy that is hard to shake. By underplaying their roles, Birkin and Gainsbourgh create a sense of claustrophobic creepiness that permeates the entire movie. While the film's central themes may be difficult to swallow, any viewer will be left with strong opinions, which is exactly what a film such as this should do. Cement Garden is based on a book by Ian McEwen, whose equally disturbing novel The Comfort of Strangers has also been made into a film.