Everyone who came to the strange gym class was looking for something else. What they found was the mysterious Mrs Powell and Pashki, a lost art from an age when cats were worshipped as gods. Ben and Tiffany wonder: who is their eccentric old teacher? What does she really want with them? And why are they suddenly able to see in the dark? Meanwhile, in London's gloomy streets, human vermin are stirring. Ben and Tiffany may soon be glad of their new gifts. But against men whose cunning is matched only by their unspeakable cruelty, will even nine lives be enough?