This is the second book in the Protector of the Small quartet.
The side flap says:
Summer is over and Keladry of Mindelan is back in training at the royal palace- no longer on probation, but an official page now. Three more years of instruction lie before her. She knows that each year the training will be more grueling and that she will have to prove herself over and over. She will have to battle bullies- including her archenemy, Joren- and her nearly crippling fear of hights. Kel also knows that she has a circle of solid friends, from the funny Neal to the teasing Cleon, and the support of her ill-tempered gelding, Peachblossom. What Kel doesn't know is that the years will hold many surprises. She will make new friends, draw the attention of the King, and save several lives. She will also be thrown into a situation in which she must take control- an act of courage, skill and intuition that will affect how everyone sees her and change forever the way that pages are trained.