Moonheart contains the best elements of a mystery novel in a setting that encompasses both magical and realistic plot devices. The novel is somewhat convoluted in that it struggles to maintain a tight plot while straddling the past and present. This proves to be difficult to orchestrate at times because of the number of fresh inventions Charles de Lint brings to this novel. The entire novel is posited on the possibility that Vikings came to North America before Christopher Columbus and recognized fairies in North America, but as manitou rather than fairies. In this, de Lint seems to be exploring the similarities between the two traditions rather than the differences.
The idea of spiritual progression referred to in Moonheart as the Way is central to the plot. The idea of finding “Taw,” something akin to inner peace or inner stability, is another key element. Good and evil do battle; however, in Moonheart, good and evil are not necessarily stagnant concepts. Thomas Hengwyr was an evil man in the past who through one thousand years of being trapped in stone managed to disavow his evil nature. De Lint raises the question of what happens to the evil people discard in their own natures. In Moonheart, this evil, Mal’ek’a, takes on a life of its own.
De Lint writes fantasy while keeping the characters firmly grounded in reality. In Moonheart, he uses Tucker, Walters, Gannon, and the Royal Canadian Mounted Police to involve the reader in the present-day conflicts surrounding this upset in reality. The story begins in present reality, veers into the world of fantasy, and returns to the world of reality in the end, with only a few marks of the tragedy to remind the characters of the incredible journey they have taken.