Set in a future world where America has lost the war on drugs, an undercover cop, Fred, is one of many agents hooked on the popular drug Substance D, which causes its users to develop split personalities. Fred, for instance, is also Bob, a notorious drug dealer. Along with his superior officers, Fred sets up an elaborate scheme to catch Bob and tear down his operation.
-from the Rolling Stone review of Scanner Darkly, a film by Richard Linklater, starring Keanu Reeves, Robert Downey Jr., Woody Harrelson and Winona Ryder. It is based on the 1977 book by Philip K. Dick. Check out the official website as well as the Variety review. It premiered at the Cannes Film Festival earlier this year and has its U.S. release on the 7th of July.