A Court of Silver Flames

The fifth book in my favorite Thorns and Roses series. This one moves away from Feyre and follows her sister Nesta, who has been shutting everyone out since the war. Her family and the Night Court step in and send her to train with Cassian, a warrior she can barely stand, and to work in a library where she finds unexpected friends. While Nesta deals with her past and her own power, a new threat appears that could pull the courts back into conflict. It’s the longest book in the series and has more explicit romance than the earlier ones, so it’s better suited to adult readers.