Library Journal: The Spires have kept humanity safe from the dangers of the surface of the world, but now war looms between Spires Albion and Aurora, as other Spires must begin to choose sides to ensure their survival. A trade summit at Spire Olympia is the opportunity for Lord Albion, the Spirearch, to secure the alliances needed to hold off Aurora, and he sends Captain Grimm and his airship, the AMS Predator, to support the diplomatic mission. When Aurora’s Armada reveals a secret weapon that can destroy entire Spires, it will take diplomacy, duels, and incredible skill to align the Spires with Albion—if it is not already too late. Multiple points of view from established and new characters widen the worldbuilding. With eight years between books, fans will enjoy reconnecting with the characters through a reread of the first book, yet new readers can also read this as a stand-alone. VERDICT Butcher’s long-awaited sequel to The Aeronaut’s Windlass is an exciting epic fantasy, set in the sky and filled with airships, magic, and the connections of blood and found family.