使徒行者 (Line Walker) (Blu-ray release 2016-10-28) is a spinoff from a 2014 Hong Kong TV series of the same name. I’m glad this movie is self contained and complete – it does not require knowledge from the TV series. The distinctive feature here is that it has more undercover agents than the usual undercover police drama. Attempting to enrich the movie, a lot of plot / action / twists / backstory / comedy is crammed into it, so the plot feels a little convoluted for its duration, and perhaps somewhat preposterous, but it is still entertaining. For a Hong Kong TV series that gets turned into a movie, this result is respectable, since there are disastrous efforts in the past.