Champion of the Ghosts - Anthologies, #7

Sixteen years old, Caina is a student of the Ghosts, the spies and agents of the Emperor of Nighmar, and from them she learns the arts of stealth and infiltration, of disguise and intrigue. If she survives, she will become a nightfighter, one of the elite agents of the Ghosts. For the Empire is in deadly danger, and needs the nightfighters of the Ghosts. Either Caina will become a nightfighter, or the enemies of the Empire will kill her...
Originally published as the novellas GHOST DAGGER and GHOST THORNS, and the short stories GHOST CLAWS, GHOST LIGHT, GHOST CLAWS, GHOST OMENS, GHOST UNDYING, THE FALL OF KYRACE, and GHOST ARIA.