Return to the Fractured Planet(1999)

Paul Cornell

Things aren't going well for Bernice. Her home world, Dellah, has been taken over by sadistically evil beings with god-like powers. Her university is a burnt-out ruin. And the infection in her head could kill her at any time. But when she hears of the horrors that befell the planet Sharabeth, she suspects that something from Dellah has escaped through time. She embarks on what she knows may be last quest.