Dex works as a gardener for Dr Jefferson at his home on Hexam Place in Pimlico: an exclusive street of white-painted stucco Georgian houses inhabited by the rich, and serviced by the not so rich.
The hired help, a motley assortment of au pairs, drivers and cleaners, decide to form the St Zita Society (Zita was the patron saint of domestic servants) as an excuse to meet at the local pub and air their grievances.
When Dex is invited to attend one of these meetings, the others find that he is a strange man, seemingly ill at ease with human beings. These first impressions are compounded when they discover he has recently been released from a hospital for the criminally insane, where he was incarcerated for attempting to kill his own mother.
Dex's most meaningful relationship seems to be with his mobile phone service provider, Peach, and he interprets the text notifications and messages he receives from the company as a reassuring sign that there is some kind of god who will protect him. And give him instructions about ridding the world of evil spirits...
Accidental death and pathological madness cohabit above and below stairs in Hexam Place.