Built By Magic by Jenna Wolfhart

When expert archer Frida decides to join the family Assassin’s Guild, she’s given an induction task. She’s to track down an orc named Rune and steal his dragon. And if she brings the guild his head, even better.
But when she finds Rune, there’s no dragon. Only a grumpy orc, hidden in the forest and building homes for the folk of the nearby villages. Frida realizes he must be hiding the dragon somewhere else.
She conjures up a plan. She’ll worm her way into his life, pretend to be a friendly new arrival to his island, and get him to trust her enough to spill his secrets. Within a few weeks, she’ll have that dragon.
But as she and Rune grow closer, unexpected desires storm between them. Frida starts to question her future—and her past. And as the days turn to weeks, she must decide if she can complete her quest and fully give her heart to the guild.
Because it might just belong to someone else.