Throughout all of known Ecto-Space, tyranny in all its forms has been opposed – and often humiliated – by a small, bionic ferret named B.E.S.. and her mysterious Mistress. However, when you and your best friend are space-faring heroes fighting evil, you tend to make a few powerful enemies along the way and from time to time, you need to lay low.

Having recently defeated the despot known as Kebek, B.E.S. and her Mistress have been hiding out on the planet Jokastarna, enjoying a life of luxury at Emperor Lukor's palace. Yet the Mistress longs to return to a life of adventure. But when she tests out her unstable time machine, the duo are plunged into an underworld populated by superstitious, disease-ridden beings who worship unseen masters.

It isn't long until B.E.S. and her Mistress find themselves in danger from all corners from tyrants and ghosts!