Zoe faces real hardship — poverty, a broken family, an unpleasant stepmother — but keeps going. Her love for Gingersnap is what gives her life colour and hope.
The bond between Zoe and Gingersnap is the novel's warmest element. Walliams presents animal companionship as a genuine source of comfort and joy.
Burt's van looks ordinary and friendly. His business hides something genuinely horrible. Walliams uses this to explore the idea that cruelty can hide behind cheerful appearances.