Jonne left his home and joined the Guardsmen of Valdemar, partly due to lack of acceptance by his family. His attraction to men turns out to be an advantage when he’s assigned to the handsome Herald-Mage Vanyel Askhevron. His encounter with the dreaded Demon-Slayer prepares Jonne to deal with a minor demon of his past.
Vanyel is the main character in Mercedes Lackey’s three Valdemar books called the Last Herald Mage series. This story relates to the short interlude in Book 2 with Guardsman Jonne, whom Vanyel met during his Border duties of defending Valdemar against their traditional Karsite enemies. Yfandes is Vanyel's Companion (best explained as a white magic horse). Small parts of the book are cited.