Art & Artifice. The Shard of Elan, #1.5

The defensive new shield to protect the human world from marauding Ryuven is not yet erected, and Commander Shianan Becknam has been assigned to invesigate a series of Ryuven raids on a farming village. The grey mage Ariana Hazelrig is assigned to his company, so he must negotiate their fledgling friendship in a formal line of command. When a watch goes wrong and Ariana suffers an attack while on guard, she begins to look at other culprits.
But protecting her people is only part of her mission. This addition to the Shard of Elan series can be read alone, but fans of the series will find more in the story.