Black Lake

9.00pm BBC Four

The dark mid-winter nights are perfect for a supernatural horror story and here’s a tale to send a shiver down the spine.

A boat carrying a group of people arrives at an isolated Swedish island, base of life coach Uno Leijon, whose treatment for addicts is somewhat controversial.

It’s the latest incarnation of an island with a very dark past: an 18th-century redout for cholera patients, a wartime refugee centre, and a place to hold juvenile delinquents in the 70s.

With no possibility of leaving the island, the six addicts face a trying time during a fortnight of Leijon’s boot camp.

When an old murder mystery rears its head, the patients face being another part of the chain in a tragic history.