PREVIEW: Walter Presents - The Devil's Throat, Channel 4

To coincide with the launch of the full series on All 4 from Friday 6 August, the first episode transmits on Channel 4.

Walter Presents - which showcases the best foreign language drama series from around the world - continues with this riveting Bulgarian crime thriller. In Smolyan, a sleepy tourist town nestled in the Rhodope mountains, a chalet keeper discovers a dead body at the edge of a lake.

Detective Filip Chanov finds out that it's the body of a retired cop while the medics discover that the body's eyes have been replaced with sheep's eyes. The police suspect that the eye swap is a form of religious symbolism.

Next, Filip is confused by the sharp-witted and mysterious Mia Yazova who is playing a double game. When the town mayor wants big city cops to take over, pressure mounts, and to add to the mystery, an elderly blind woman tells Filip that the death is the work of the devil. How dark will this investigation become?