Umineko No Naku Koro Ni Episode 2: Turn Of The Golden Witch

In Fall 1986, Battler Ushiromiya and eleven of his family members are reunited on Rokkenjima for the purpose of discussing how the head of the family's fortune will be divided upon his impending death. When a typhoon hits the island, everyone is trapped and murdered supposedly by the Golden Witch in her efforts to revive herself.
When Battler refuses to acknowledge the existence of magic and witches, Beatrice the Golden Witch, appears before him and challenges him to save his family by proving that neither she nor magic exists. To save his loved ones, Battler is forced to observe the events of Rokkenjima again and explain how all the murders occurred without magic or otherwise submit to Beatrice and acknowledge her existence as a witch.