War Mage by Jordyn Alexander

Adara Flameborn was raised by The Mage’s Tower, the other mages there the only family she’s ever known.

When her closest friends are all killed in the war with Orik, Adara decides in her rage and grief to kill the only person left to blame: Adrik’s Queen Adalind. When her assassination attempt is foiled, Adara finds herself imprisoned in a room that cuts her off from her magical gift and tortured by a cold-hearted orc that she grows to hate. But when the queen comes to her with a chance for clemency if she takes on a dangerous mission with the very same detestable orc, she has little choice but to say yes.
Urim ka Churnok is the orc that gets things done, no matter the actions needed or the price to be paid.
When his queen comes to him with a high-stakes mission that could turn the tide of the coming war, he accepts without question. Even though it means going into enemy territory with a mage who hates him, likely never to return.
When the two make it into Barakrin, the enemies’ territory, everything goes wrong and they find themselves chained together, on the march to be blood slaves for Lord Grazrath himself.

Forced together, they find an attraction grow between them, against their wills and common sense. When Urim must pick between Adara and finishing his mission, will he save the woman he has come to care for? Or will he let her burn?