From IMDB:

The Tunnel is set against the backdrop of Europe in crisis. When a prominent French politician is found dead on the border between the U.K. and France, detectives Karl Roebuck (Stephen Dillane, “Game of Thrones”) and Elise Wassermann (Clémence Poésy, “Harry Potter and the Deathly Hallows Part II”) are sent to investigate on behalf of their respective countries. The case takes a surreal turn when a shocking discovery is made at the crime scene, forcing the French and British police into an uneasy partnership. As the serial killer uses ever more elaborate and ingenious methods to highlight the moral bankruptcy of modern society, Karl and Elise are drawn deeper into his increasingly personal agenda.

From Amazon Prime you can download the 10 episodes, each episode lasting about 45 minutes.  Both French and English are spoken.

Be prepared for a somewhat grim story in which the psychopathic “Truth Terrorist” enacts a series of wrenching murders. For example, the story starts when the French and British detectives meet inside the channel tunnel at the exact half point which is the dividing line between Britain and France. Lying on that midpoint are two body halves (each from a different person) joined to look like one person. This should give you an idea of how grisly the plot becomes.

If you can put that gore behind you, you might enjoy the personal crux of the story: Elise, the French half of the team, suffers from an extreme case of Asperger’s Syndrome. She just does not understand human emotions, or as we might put it, she is just plain clueless. However both she and the British detective Karl are equally obsessively dedicated and very smart detectives.  Between them the interaction is entertaining.

And yes, there is quite a bit of sex, meaningless and otherwise.

If you can stand the harsh crimes, the suspenseful story is a good watch.