In Demon, a bridegroom is possessed by an unquiet spirit in the midst of his own wedding celebration, in this clever take on the Jewish legend of the dybbuk. Peter (Israeli actor Itay Tiran), has just arrived from England to marry his beautiful fiancée, Zaneta (Agnieszka Zulewska), at her family's country house in rural Poland. The old homestead is a gift from his future father-in-law, and Peter is excited to renovate it into a home for his new family. While inspecting the grounds on the eve of his nuptials, Peter finds skeletal human remains buried on the property. Haunted by his discovery, Peter slowly starts to unravel while the joyous and drunken traditional Polish wedding goes on around him; and soon, he is overcome by what seem to be epileptic fits, panicking his bride and scandalizing his father-in-law. As the night wears on, it becomes apparent that there is an uninvited guest at the wedding, that she is lonely - and that she is very, very dead.