Shadow of Night is the second book in the All Souls Trilogy, preceded by A Discovery of Witches (2011) and followed by The Book of Life (2014). There are no breaks in time or action between the sequels, making their narratives highly dependent. Shadow of Night contains minimal explanatory background information on the various characters, relationships, and plot points from A Discovery of Witches. The following knowledge of the first book is vital to understanding Shadow of Night.

A Discovery of Witches introduces Diana Bishop, a history of science professor. Though Diana is a witch, she doesn’t often use her powers like her Aunt Sarah, who raised her with her partner, Emily, after Diana’s parents died. Because of the mysterious nature of her parents’ deaths, Diana avoids magic. Then, when working in Oxford’s Bodleian library, she puts in a request for an illuminated alchemical manuscript called Ashmole 782. She knows immediately that the manuscript is magical. Three pages are missing, and the words are swimming as if looking for the lost pages. Diana cannot read the manuscript, but she senses its enormous power and returns it.

The Ashmole manuscript created a magical wave that was felt by all the nearby “creatures”—the collective name for witches, vampires, and daemons.