The Serpent and the Rainbow

Dennis Alan, an ethnobotanist/anthropologist from Harvard University, narrowly escapes the Amazon Jungle and returns to Boston. Word of his exploits gets around and he is approached by a large pharmaceutical corporation looking to investigate a drug that is part of the Voodoo religion in Haiti that they want to acquire and mass produce. They send him to Haiti to find out about the drug, but he winds up learning more about zombification instead. In essence, the drug is an alternate and less dangerous method of anesthesia.