Horror maven Wes Craven attempted a slight change of pace from his usual slasher movie milieu with this chiller loosely based on a true story. Bill Pullman stars as Dennis Alan, a Harvard researcher sent to Haiti by a pharmaceutical company to investigate the zombie legend and any possible connection it might have to a rumored drug that could be used as a new breed of powerful anaesthetic. Once on the Caribbean isle, Alan is aided by a good voodoo priest or "houngan" (Paul Winfield) and his daughter (Cathy Tyson), who runs a local clinic. Alan's search also pits him against an evil houngan, Dargent Peytraud (Zakes Mokae). Peytraud also controls the Tonton Macoute (the Haitian secret police), who are involved with soon-to-be-deposed dictator "Baby Doc" Duvalier. The Serpent and the Rainbow was based on the book of the same name by Wade Davis, an ethnobotanist whose real-life hunt for the zombie drug was credited with cracking the medical mystery behind the myth.
~ Karl Williams, All Movie Guide