The Valdemar Legacy is a horror mystery movie about a dark legacy that unfolds as a locked-door discovery of a dead body leads to a series of eerie events. A messenger delivering a bouquet finds himself trapped in a sinister office with a talking cat and a mannequin. As he tries to solve the mystery, he becomes the target of a relentless chase.

The movie revolves around a series of events involving rapid aging, monsters, Cthulhu, human sacrifice, occult rituals, human skulls, taser guns, caves, gypsies, mannequins, cults, tarot cards, walls of photographs, levitation, the Necronomicon, being locked in a room, H.P. Lovecraft, a kidnapped baby, and murders with an axe.