Gruesome axe murders plague the menacing ancestral castle of the Halorans, a family whose heritage includes greed, deception and death. Louise Haloran wants to enjoy a piece of her husband John's fortune, but when he suddenly dies without including her in his will, the scheming wife conceals the death from the family. The castle is haunted by the spirit of John's long dead younger sister Kathleen. When Lady Haloran announces she will give all her money to charity in the name of Kathleen, greedy Louise concocts a plan. Arranging some of Kathleen’s possessions in the pond where the girl drowned, Louise emerges from the dark waters only to be attacked and murdered. The weapon: a razor-sharp axe! A killing spree erupts on the Haloran estate, seemingly motivated by the murderer's obsession with Kathleen. The surviving Halorans must discover the killer's identity before their fate is sealed.