Binding Souls(2019)

University students are assigned to do special research in The Moral Education College during summer vacation. The school has been occupied by the Japanese to do cruel human experiments, they found an alumni records about ghost experience, and also found that some girls was mysterious disappeared. A staff of the school, Miss Fang led them to know the environment, then a chain of strange things happened in that evening, and finally they are forced to flee to a century-old tree, unexpectedly they saw the Principal of the college dig out some bones unconsciously under the tree. Are the bones and all the strange things related? Can the five people go out of the school safely?