The murder of the ex-wife of Doctor Sam Charney (Rutger Hauer) leads Detective Della Wilder (Pam Grier) to uncover a series of women's murders somehow linked to a big pharmaceutical company.

A young couple, Mary and John, awaiting a baby is in search for a house when they decide to buy that lovely old villa they found by coincidence. What they both do not know is that Myron, the owner of that villa and their new neigbour, is a dangerous psychopath and that Mary reminds him of his dead mother. Mary begins to wonder about Myron's odd behaviour, but everybody thinks Mary's fears are due to her being pregnant.

Greed, betrayal and vengeance set the stage for this Sir Arthur Conan Doyle classic. Mary Morstan, a young governess, has been receiving a rare and lustrous pearl annually from an anonymous benefactor.