Lin Zixiong (Zheng Geping) dies after being hit by a car, and the only witness seems to be his stepson "Popiah" (Deng Mao Hui), a quiet young boy with no friends besides a gigantic tree. Police investigator Jiang Liangxing (Phyllis Quek) becomes convinced the driver was Lin's wife Guo Meifeng (Zoe Tay), whose first husband Xie Wenguang (Tse Kwan-ho) disappeared 5 years ago. Meanwhile, Jiang's boyfriend and pathologist Wu Chongzhe (Francis Ng) discovers a mysterious fungus in Lin's heart. He also befriends Popiah and learns that Lin had sexually abused him. Perhaps the answer to everything lies in the gigantic tree.