A birthday celebration turns grim when a ritualistic murder reveals a victim with a hidden, non-human nature. FBI Agent Lily Yu's twenty-ninth birthday is interrupted by the discovery of a naked, tattooed man in Northern California. The victim, David Pruitt, was a close friend of Rule Turner, a prince of the lupi, a supernatural race. As Lily investigates, she uncovers that David was not human, and the killer has not yet finished their work, suggesting a deeper, darker magic at play than initially suspected.

Praise for Eileen Wilks' Novels of the Lupi highlights their ability to 'grab you on the first page and never let go,' with reviewers noting they are 'full of intrigue, danger, and romance.' Readers remember Wilks' characters long after finishing the books, suggesting a strong connection to the world and its inhabitants. As an urban fantasy novella set within this established world, 'Human Nature' likely offers a concentrated dose of the series' signature blend of supernatural elements and compelling mystery. The inclusion of an excerpt from 'Mind Magic' further signals its connection to a broader, popular series.