A police detective must solve a brutal murder to prove his partner's innocence and unearth the truth behind Hong Kong's police force. The investigation brings him to an unlikely collaboration with an inspector from the Narcotics Bureau, whose motives may not be what they seem.

Ken, a shrink, is in his 30s. His wife, Flora, was his high school sweetheart. They have been married for over a decade and Flora's face has already been weathered. In his prime, Ken cannot help but think that something is missing from his life. To celebrate their 15th anniversary, Ken and Flora go for a walk in the hills. Flora loses her balance and when she is about to fall off a cliff, Ken does not save her. Flora has died and strange things start to happen at home....