When the Doctor arrives in the 19th-century village of Klimtenburg, he discovers the residents suffering from some kind of plague: a 'wasting disease'. The victims face a horrible death — but what's worse, the dead seem to be leaving their graves. The Plague Warriors have returned. The Doctor is confident he knows what's really happening; he understands where the dead go, and he's sure the Plague Warriors are just a myth. But as some of the Doctor's oldest and most terrible enemies start to awaken he realises that maybe — just maybe — he's misjudged the situation.