Throne of Glass #3: Heir of Fire by Sarah J. Maas (author) (UK edition)

Some people are whispering that the fierce, wild Celaena Sardothien is broken. We’ll believe that when the sun rises at midnight. Yes: she’s been brought low. She’s faced dire battles and shattering heartbreak. Now the savage death of her dearest friend. This is her darkest hour. But will she quit? Like heck. Vengeance is so more her style. She is bound to serve the King of Ardalan, but his days are numbered. Make no mistake: he will pay for what he did. But first, Celaena must face her darkest demons and defeat a brutal army. Think she can do it? Go, Celaena. We don’t doubt you for a second.