The BBC has released a trailer for its adaptation of China Miéville’s 2008 novel The City and The City. The four-episode series will begin airing in the UK on Friday, April 6th.

The BBC and Mammoth Screen studios (which is also working on a new BBC adaptation of H.G. Wells’ Victorian-set novel The War of the Worlds), picked up the adaptation in 2015, with screenwriter Tony Grisoni (Fear and Loathing in Las Vegas, Philip K. Dick’s Electric Dreams) attached to write. The series follows Tyador Borlú (played by The Walking Dead’s David Morrissey), who is an inspector with the Extreme Crime Squad in a fictional city called Besźel.

The story is set in a unique world. Two cities — the poor Besźel and wealthy Ul Qoma — occupy the same geographic space, with populations that aren’t permitted to interact and have their own unique cultures, languages, and architecture. The citizens of each city can sort of see one another, but are conditioned to ignore denizens of the other city; “breaching,” or breaking that separation, is a grave crime, and it often results in residents being deported by a mysterious secret police force. Borlú is tasked with investigating the murder of a Ul Qoma student named Mahalia Geary. He must piece together the circumstances of her murder, and how it’s connected to the separation between the two realities.

Miéville is known for brilliant, genre-bending novels like Perdido Street Station, Kraken, and Embassytown. The City and The City is a particularly acclaimed mystery that examines the barriers societies erect between different populations and the powerful political structures that enforce them. There have been notable stories in recent years about alternate worlds — most recently Starz’s fantastic series Counterpart — but Miéville’s surreal, intriguing take on this particular trope makes excellent source material.

An American release date has not yet been set, but the show will begin airing on BBC Two next week.