Hired to steal the fabulous Queens Diamond, pint-sized jewel thief Calvin Simms (Marlon Wayans) and his dimwitted partner Percy (Tracy Morgan, TV's 'Saturday Night Live') stash the stone in Vanessa Chase's (Kerry Washington, Ray) handbag when their getaway plans go uproariously awry. Discovering Vanessa's husband, Darryl (Shawn Wayans), who's hopelessly obsessed with becoming a father, Calvin trades in his duds for diapers and poses as an abandoned baby. Suffering through a host of hysterical humiliations and outrageous family outings, Calvin desperately tries to retrieve the gem before his cover is blown, and Darryl and Vanessa really cut him down to size.