Sorority row features a prank gone horribly wrong megan's sorority sisters do what to her?

They did a prank on one of the sisters ex boyfriend which was she pretended to be dead so they brought the "dead body" (alive) to a disgusting old place. They told everyone to get a sharp rock and the boy stabbed it right into Megan's Chest!!! Then she was really dead. They threw her body down a well and left it there. On graduation day the principal announced Megan was missing. Everyone that was a part of the crime felt really guilty but did not show it. Then some ones cellphone rang and it was a picture of the rock and a black hooded creature. Megans spirirt still haunts the sorority sisters from now until they are dead.........