Chess-hustling, ticket-scalping Chris Rock learns that his separated-at-birth twin brother was an ultrasophisticated CIA operative killed while on a sensitive mission. Now the CIA wants him to impersonate his twin and retrieve a suitcase-sized nuclear weapon. Anthony Hopkins is the unsmiling, world-weary spymaster who must train Rock and keep him alive. As in all Jerry Bruckheimer-produced summer blockbusters, the premise is paper-thin and the action sequences play out with assembly-line regularity. Assassins chase Rock through an apartment building, firing machine guns all over. Then Rock and Hopkins take part in a wild car chase. Then they're surrounded by eastern European baddies wielding more machine guns. And on and on. Director Joel Schumacher does a fair job of managing the chaos, but after a while you get tired of being dragged from setup to setup. 111 min.