Silver in the mist
(Book)

"Eight years ago, everything changed for Devlin: Her country was attacked. Her father was killed. And her mother became the Whisperer of Aris, the head of the spies, retreating into her position away from everyone... even her daughter. Joining the spy ranks herself, Dev sees her mother only when receiving assignments. She wants more, but she understands the peril their country, Aris, is in. The malevolent magic force of The Mists is swallowing Aris's edges, their country is vulnerable to another attack from their wealthier neighbor, and the magic casters who protect them from both are burning out. Dev has known strength and survival her whole life, but with a dangerous new assignment of infiltrating the royal court of their neighbor country Cerena to steal the magic they need, she learns that not all that glitters is weak. And not all stories are true"--Publisher's description.