Watch The Demise of the Summer Priory Full Movie Free Online 123Movies. In this film based on the novel "Demise of Serui Dugan" by the folk writer Seng Erden, the sad story of how ancient Mongolian traditional rituals, religions and sum monasteries were destroyed by the black storm of repression in the 1930s is told in "Seruun" in Binder Sum, Khentii province. Dugan" is based on the tragic fate of the monastery.