Omen of ice by Jus Accardo

Keltania Tunne has spent her whole life training to become a bodyguard for a Winter Fae. It’s the highest of honors for a druid…only when Tania arrives at the Winter Court for the first time, nothing is what she expected.
Her assignment is the heir to the throne, Valen, and he doesn’t want her protection. In fact, he wants her gone. Yesterday. But Tania will not compromise, even if he is the most arrogant jackass she’s ever met—because something isn’t right in the Winter Court.
Everyone has secrets. From the Winter Lord to the kitchen maids to the rising faction that wants the prince dead—no one is who they seem. And now it’s up to Tania to keep her sacred oath and protect Valen, even when his smart mouth makes her skate the razor-thin edge between love and hate.

But the more she gets to know him, the more she realizes his secret is the biggest of all—and might just get them both killed.