The Shepherd King series is a fantasy-based duology that includes One Dark Window and its sequel, Two Twisted Crowns. In One Dark Window, the narrative sets up the bi-directional magical system at play within the kingdom of Blunder, the duology’s central location. There are two forms of magic at work in the kingdom. The first is a wild magic deriving from the Spirit of the Wood. This magic is often degenerative, potentially dangerous, and acquired after succumbing to the Spirit’s black-blood infection and magical fever. Ravyn’s brother Emory, for example, has the unique power to “read” individuals in intimate details and at times glimpse their future, but using his powers slowly erodes his mind and body.

The second form of magic is that of the Providence Cards, which are twelve types of magic cards created by the Shepherd King to provide stable magic that comes with a determined cost. If someone were to use the Mirror Card’s invisibility for too long, for instance, they would begin to see dead spirits. By creating these Cards, however, and causing citizens to turn away from the Spirit’s blessings, the Shepherd King inadvertently provoked the Spirit into unleashing the mist.