When a human head is discovered, the paths of a female student, a cellist, an autistic teenager, a police officer, a prostitute, a teacher and a dog are found to be serendipitously entwined. Who caused the death? What is the motive? Where is the body? Attempts to answer these questions lead to keywords starting with the letter "G". As the case is peeled back layer by layer, the complexity and desperation of the people living in Hong Kong today are slowly uncovered, and a suspenseful multifarious Hong Kong story is revealed.

Min (Jacqueline Ch'ng), Lung (Sammy Sum), Keong and Fen are business partners of an online game design company, which is on the verge of winding up due to the lack of clients. Just as things start to get worse, a mysterious lady, Mrs. Wong (Paw Hee Ching) offers them a sizable sum of money if they could complete the final stages of her deceased son's online game - Ouija Board and launch it thereafter. They readily accept the business. Soon mysterious things happen and they experience ghost sightings.