I Killed the King by Rebecca Mix; Andrea Hannah

 After a decade of war, the kingdoms of Avendell and Istellia have finally agreed to peace. As nobles and magic wielders from both countries arrive at remote Castle Avendell for a historic all-night masquerade to celebrate, King Costis summons an unlikely group to his the crown prince, his Istellian bride-to-be, his personal guard, a wild beast teamer, and the palace’s questionable new healer. But before Costis can reveal why he has gathered them, the castle goes dark.

When the lights come back, the king is dead—murdered with the princess’s knife, in a weak spot only his guard knew of, and with venom from one of the beast tamer’s monsters lacing the blade.

With no clear killer—and everyone a suspect—they make a risky Tell no one until the treaty is signed. But when a winter storm seals everyone inside and someone aware of the king's untimely death begins to pick off guests one by one, the six suspects must work together to discover who killed the king . . . before one of them is next. 

I Killed the King delivers a clever twist on the classic locked-room mystery—but with a twist: it’s less a confined parlour puzzle and more a locked-castle mystery, trapping suspects and danger across the sprawling corridors and chambers of Castle Avendell. The king’s murder, set against a peace celebration between warring kingdoms, spins a taut whodunit as snow and suspicion seal everyone inside with no one to trust. 

While the premise promises a tightly wound fantasy mystery, the writing structure leans far more into character building than world building. Rather than luxuriating in expansive setting details or crafting a fully fleshed magical realm, Mix and Hannah choose to deepen reader investment in the ensemble cast, using alternating points of view and personal backstory to reveal secrets, motives, and emotional stakes. This approach gives characters texture and invites empathy—but occasionally at the expense of broader world context, leaving the setting more as a backdrop than a vibrant, lived-in place.

Fans of character-driven narratives will appreciate the emotional depth and relational dynamics, but readers craving rich worldbuilding alongside their mystery may find the castle’s magic and politics somewhat underexplored. 

Overall, I rate this novel 4 out of 5 stars.