The Stolen Princess (Royal Blood, #4)

Over twenty years have passed since Athan Vercilla stole Princess Kayla Sipesh from Tordania against her will. However, he didn't own his most prized possession forever. Kayla escaped, finding a new life with the Nahli, far from Athan's reach.

After Athan learns she's living in the Northern Wastes a decade later, her adopted people are in danger, and she's forced to travel back to where it all began. While she's never met her brother, she must seek King Keiran Sipesh's help in planning a future war to end Lord Vercilla's tyranny once and for all.

Despite all the time that has passed, Athan's obsession with Kayla hasn't faded. He discovers she's come out of hiding when his favorite son goes missing. Getting her back under his control is his greatest desire, all of his other plans suddenly insignificant. He'll reclaim her at any cost, even if he has to kill Keiran to get him out of the way first.