In Wes Craven's career there were few bright spots between the peaks of A NIGHTMARE ON ELM STREET and SCREAM. 1988's THE SERPENT AND THE RAINBOW is one of them, and though it's not Craven's finest hour, it still beats DEADLY FRIEND by a country mile.
Based on Wade Davis's factual account, SERPENT deals with Bill Pullman (years before he became a leading man in bland romantic comedies) investigating Haitian voodoo rituals on behalf of a pharmaceutical corporation; they believe the zombie power used in these ceremonies would make for a revolutionary new anesthetic (personally, I'd be a little freaked if my doctor used Zombinol during my procedure, but that's just me). Pullman's research comes across the radar of Dargent Peytraud (Zakes Mokae, in a great sinister turn), an officer in Papa Doc Duvalier's regime who has some rather persuasive methods to ensure that Haiti's secrets remain that way.
Since the film's true focus is on mystery and intrigue, Craven (most likely at the behest of studio executives) squeezes in a few scare-laden dream sequences to maintain a "horror" element. Though the perception-skewering approach Craven uses here is done with a sharper visual flair than the similar tactics in ELM STREET--nor are they as disruptive as those in SHOCKER--these scenes undermine the story and threaten to reduce it to a mere shock show. The serious and dramatic aspects of the tale disintegrate completely into a carnival funhouse during the climactic showdown crammed with laughably-rendered visual effects (which feel like last-minute additions "suggested" by helpful test screenings).
THE SERPENT AND THE RAINBOW could've been a successful meditation on the connection between the scientific and spiritual worlds. Craven's reputation as a horror director may have been its ultimate undoing, since certain expectations on either side--a filmmaker who wants to create a serious, adult film, and a studio wanting something that would draw the profitable teen crowd--would have been tough to bring together. It's still a fascinating glimpse into a world that's frequently misunderstood, and worth at least a look.