Since its local release in May, Soi Cheang’s action sensation has become Hong Kong’s second-biggest domestic hit ever, earning $13.7 million in a city of just 7.2 million residents.

But not only has the film reinvigorated Hong Kong’s fabled martial arts genre but also it has revived — if only fleetingly — one of the world’s most alluring architectural monstrosities: the Kowloon Walled City. Once the most densely populated place on earth, the Kowloon Walled City was an effectively lawless enclave of Hong Kong that grew from the footprint of a small Chinese military fort into a labyrinthine urban microcosm. With no formal infrastructure, its towering, interconnected buildings were constructed haphazardly, creating a dark maze of narrow alleys and secret passages.

Before its demolition in 1993, the Walled City had over 35,000 people living in an area of less than seven acres (which amounts to more than 44 times the urban density of Manhattan). Related Stories takes place inside the Kowloon Walled City during the pivotal year of 1984 when Britain formally agreed to return the colony of Hong Kong to China. Packed with local action heroes of past and present — Louis Koo, Sammo Hung, Aaron Kwok, Richie Jen, Raymond Lam, Terrance Lau, Kenny Wong, Philip Ng and others — the film tells the story of a young refugee (Lam) who’s forced to seek haven in the Walled City to avoid being extorted by a local crime boss.

Inside, he begins to find his place among the enclave’s.