Umineko no Naku Koro ni takes place primarily in the year 1986, during the time frame of October 4 and October 5 on a small, secluded island named Rokkenjima (六軒島) owned and lived on by Kinzo, the head of the wealthy Ushiromiya family. Kinzo is expected to pass soon due to his age, and so his 4 children and their families arrive on the island to discuss how Kinzo's assets will be divided after his death for the annual family conference. But when a typhoon hits the island, a ghastly game begins, starting with the murder of six people and the discovery of a letter signed by Beatrice, the island's golden witch of legend, beckoning the family to solve her epitaph and find the island's hidden gold before it is too late.

[Edited from When They Cry Wiki]

Umineko no Naku Koro ni Chiru is the second set (EP5-EP8) of stories, the "Breakdown" episodes.