The Red House is the mansion of the late M. G. Mason, a brilliant puppeteer and taxidermist. Descendants almost forgot about him, but now the heirs decide to sell Mason's works, and his creations will again come to light. An employee of the auction house, Katherine Howard, comes to evaluate the collection. Seeing the artist's exquisite and sinister dioramas dedicated to the horrors of the First World War and strange dolls, she realizes that this is a real treasure that can bring millions. But the Red House hides many secrets as dark and dark as Katherine's own past. At night, the estate comes to life, strange steps are heard here, and strange shadows are visible on the stairs. In addition, there is something terrible in the history of Mason himself and his creations, and soon the boundaries between reality, madness and nightmare begin to crumble, and Catherine’s life changes forever.