"An ancient evil from the dawn of time? It took over the proto-Paracastrians and manipulated their evolution to its own ends? That's a bit of a cliche, isn't it?"
Welcome home Wil. And here's your welcoming committee: a platoon of armed Paracastrians, a fire-breathing temptress with a dotty dad, and several dozen bounty hunters all after your head. It's just like you'd never been away.
Paracastria has changed much in the years since the Doctor's last visit; the natives have taken over and cast all humans into a subservient role. But why have they done this? And moreover, why are they locking people up and experimenting on them? And why is there a daytime curfew?
Overtaken by events, will the Doctor be unable to prevent a clash that has been brewing since before the Paracastrians grew legs? Can he rescue his friends before the situation gets entirely too hot for comfort?
But there's someone else on Paracastria... Someone who should have left a long time ago. Someone who may, just may, have caused this whole situation to come about.