Feyre finds herself back in the Spring Court, playing a dangerous game of subterfuge as a spy for the Night Court. Maas masterfully crafts a narrative riddled with tension as Feyre walks a tightrope, feigning loyalty to Tamlin while secretly working to undermine his alliance with Hybern. This theme highlights the complexities of war and the sacrifices necessary for the greater good, even if it means betraying those you once considered allies.

With Prythian facing annihilation, Feyre realizes that the only way to defeat Hybern is to unite the divided High Lords and their courts. Throughout the book, she strives to mend broken bridges and forge new alliances, emphasizing that even sworn enemies must set aside their differences in the face of a common enemy. This theme underscores the strength found in diversity and the importance of cooperation in overcoming adversity.

War tests the limits of love and loyalty. Feyre and Rhysand's bond faces immense challenges as they grapple with the potential costs of their fight against Hybern. Maas explores the depths of their love, highlighting their willingness to sacrifice everything for each other and the future of Prythian. This theme reveals the enduring power of love and its ability to thrive even in the darkest of times.