College student Sarah Chong returns to Hong Kong when her grandmother falls ill, temporarily leaving her doting boyfriend behind in L.A. She arrives in Hong Kong during Ghost Month, when tradition holds that the gates of hell open and demons of the dead return. Her grandmother becomes obsessed with performing rites to appease the spirits, and her mental and physical health worsen despite Sarah's best efforts. Sarah reunites with her old Hong Kong high-school friends for the first time since their former classmate committed suicide. As her grandmother deteriorates and dangerous things start happening around Sarah and her friends, she fears what they did in the past has come back to haunt them.
—Circle of Confusion