Certain themes have become trademarks of Westall's work over the years.

One theme introduced in Westall's first novel,The Machine-Gunners, involves the ability of young people to act independently and to solve problems without the help of adults. The adults of "The Haunting of Chas McGill" are obstacles rather than aids.

Connected to this theme is the sense that it is individuals in their most isolated and besieged moments who become most susceptible not only to the threats of the supernatural but also to the pitfalls of everyday life. Perhaps the best example is Sally in "The Creatures in the House." The creature in the story feeds "on women alone; women in despair." Alone in her new house, afraid of what she will become, Sally becomes prey for the creature. It is only through her initiative in surrounding herself with cats and confronting the...