Seanan McGuire 
Late Eclipses (Toby Daye Book 4) 

The fourth instalment of the highly praised Toby Daye series.October Toby Daye, changeling knight in the service of Duke Sylvester Torquill, finds the delicate balance of her life shattered when she learns that an old friend is in dire trouble. Lily, Lady of the Tea Gardens, has been struck down by a mysterious, seemingly impossible illness, leaving her fiefdom undefended. Struggling to find a way to save Lily and her subjects, Toby must confront her own past as an enemy she thought was gone forever raises her head once more: Oleander de Merelands, one of the two people responsible for her fourteen-year exile.Time is growing short and the stakes are getting higher. With everything on the line, Toby will have to sort truth from lies to the people she loves most. If she can t, Toby will be forced to make the one choice she never dreamed she’d have to face again…