Forest of Death

Detective Ha (Shu Qi) is trying to solve a rape/murder case but hasn't got a whole lot to go on. She heads out to the forest where the girls were found killed to investigate and quickly realizes that there's something mysterious about this forest. She gets in touch with Steven who has written a thesis that plants are sentient creatures. Could the trees be the answer to this case, or is there something even more absurd lurking in the deep forest?