Betsy Connell (Frances Dee) travels to the Caribbean island of Saint Sebastian to play nurse to Jessica Holland (Christine Gordon), who may be an actual zombie. While there, she's involved in sort of a romantic triangle with brothers Wesley Rand (James Ellison) and Paul Holland (Tom Conway). Mrs. Rand (Edith Barrett) doesn't live on the plantation with her sons, but plays a big part in what ultimately happens.
Very moody, as I would expect from producer Val Lewton and director Jacques Tourneur (Cat People, The Leopard Man). However, there's surprising depth of character in the screenplay by Curt Siodmak and Ardel Wray. Much better than I anticipated.