Doctor Who

BBC1, 6.25pm, today

The Doctor and her companions receive nine separate distress calls, all originating from the mysterious planet of Ranskoor Av Kolos, which turns out to have been the site of a terrible battle.

As further secrets are uncovered and strange forces gather in the mists, the only clue as to what has happened is a commander with no memory. Mark Addy guest stars in the final episode.

The Doctor returns for a special episode on New Year’s Day.