The Tunnel, a TV series

This joint television production - English, French - is based on the Swedish television series The Bridge, which we are now watching.  

The cover here is from the second season, which we just finished watching.

The first season started with a body found in the Tunnel, between England and France, exactly at mid-point in the Tunnel, so police forces from both countries are involved in this extremely unusual case. Both detectives involved form a unique relationship.

Warning this series can be quite graphic.

We "enjoyed" this one as it has very interesting views into opposing police forces having to come together to solve very complicated cases.