This eight-part Norwegian drama takes us deep beneath Oslo, where desperate doctor Ravn Eikanger has set up a makeshift, secret hospital in an abandoned underground station called Valkyrien.

There he plans to find a cure for his terminally ill wife after her doctors give up hope, but that takes funding, and his only help is corrupt civil-defence worker Leif Lien, who persuades Ravn to offer medical help to various shady characters from Oslo’s underworld.

The series has won awards including Best Drama in Norway, and Mark Strong is lined up to star in an English version set in London. After this episode airs, the full series is on All4.