Children of the Night Themes
The main theme is the existence of evil in the world. Fighting it is the duty of all who are able to do so. Diana Tregarde has been "called" to this responsibility by her unusual psychic strengths. She is a Guardian — a commission which has little to do with her neopagan faith. She is required to respond to anyone who calls out for help on a psychic plane.
Diana is contemptuous of those who believe "the universe is a friendly place." Such people are likely to become victims through their own naivete. In fact, in the novel, most people are unaware of the larger struggles going on around them. Thus they are likely to become pawns whenever evil forces run loose. Those tuned in to extrasensory currents, like witches/neopagans and gypsies, are somewhat more aware of such events, but also likely to attract the unwelcome attention of evil entities. Lackey's subtext thus presents a clear, consistent view of a metaphysical realm. Whether it is also a metaphor for events in the social and political arena is unclear.
There are many hints that things are not always what they seem. At first Diana cannot believe she has seen an actual vampire outside her apartment building. When he reappears, she is prepared to fight him with the prescribed weapon, a cross. Andre merely laughs and grabs her wrist, explaining he has nothing to fear from the Son of God. It turns out that he is far from being a traditional vampire; he even apologizes for taking the blood he must drink to keep up his energies. As events go on, he becomes Diana's ally and lover.
The other side of illusion is the gaki, the stalking demon, who can take on his victim's form, or even appear as a cloud of smoke with eyes. This latter ability makes smoggy cities an ideal place for him to operate. The only protection against such a danger is constant vigilance. But even that is not always enough. The author has written a scary and suspenseful story whose message is, in part, "Be wary of the unexpected — and the unremarkable."