See also Deep Secret (spoilers).
He has the help of the ghost of his own mentor, Stan Churning, who is haunting his car and listening to Scarlatti. He has a list of 5 possible candidates but none of them sound very promising. He has a hightly frustrating experience when attempting to meet the most likely, Maree Mallory. He crosses her off the list and arranges to meet the rest at a science fiction convention in a labyrinthine hotel complex.
Although magically excluded, Maree shows up, attending the con with her uncle, sci-fi author Ted Mallory, his unpleasant wife Janine Mallory, and her younger cousin Nick Mallory. All the madness of a sci-fi convention combines with magical misbehaviour to cause a truly chaotic job for Rupert who has more on his hands with the candidates than he bargained for.
Magid Candidates and their Associates Maree Mallory, Nick Mallory, Janine Mallory Ted Mallory, Tansy-Ann Fisk,Mervin Thurless, Kornelius Punt, Milan Gabrelisovic Mrs Nuttall, Derek Mallory, Robbie?, Davina?, [Aunt Irene]?