Line Walker: The Prelude

Line Walker: The Prelude is a 2017 drama produced by TVB. It is the prequel to the 2014 drama Line Walker. It stars Michael Miu, Benz Hui, Moses Chan, Jessica Hsuan, Benjamin Yuen, Pakho Chau, Priscilla Wong and Alice Chan.

Synopsis
In 2010, Cheuk Hoi (Michael Miu) secretly travels to Bangkok to conduct a drug operation with his undercover agents in Thailand. As they finish their mission and are about to leave Thailand, an explosion causes all of Cheuk Hoi's undercover agents to die in a sea of fire. At the same time, Cheuk Hoi's good friend, CIB Inspector Lai (Eddie Cheung), is killed for unknown reasons, leaving Cheuk Hoi in charge of a female cop who is not yet officially an undercover. Cheuk Hoi knows that Lai Sir still has undercover agents whose identities have been deleted. To learn the truth about Lai Sir's death, Cheuk Hoi must find all of the undercovers. He and Cheng Suk Mooi (Priscilla Wong) begin to search for the undercover agents.

Development
It was announced that Raymond Lam and Charmaine Sheh will not reprise their roles as they ended their contracts with TVB. Their roles will be replaced by Moses Chan and Jessica Hsuan, respectively.

Filming began in October 2016.