Sarah Jane finds a baby girl on her doorstep and tries to find out who abandoned her. At a nuclear power station, a beautiful woman appears out of thin air and uses alien powers to take control. She's looking for something - and realises that Sarah Jane may just have it.

Metalkind fights Fleshkind for control of Sarah Jane's new friend, Sky. Can Sky stop herself destroying the world?

The world has a brand new Public Enemy Number One - and his name is Clyde Langer.