The Elf Tangent by Lindsay Buroker

As a princess in the impoverished kingdom of Delantria, it’s Aldari’s job to look pretty, speak little, and marry a prince.

Studying mathematics and writing papers on economic theory in an effort to fix her people’s financial woes? Her father has forbidden it. With war on the horizon, they must focus on the immediate threat.
Reluctantly, Aldari agrees to marry a prince in a neighboring kingdom to secure an alliance her people desperately need. All is going to plan until the handsome elven mercenary captain hired to guard her marriage caravan turns into her kidnapper. His people are in trouble, and he believes she has the knowledge to help.
But with an invasion force approaching Delantria, Aldari’s own people need her. She must do everything in her power to escape the elves and make it to her wedding in time.
Never mind that her kidnapper is witty, clever, and offers her a challenge that intrigues her mind even as his easy smile intrigues her heart…
Aldari can’t let herself develop feelings for him. To fall in love and walk away from her wedding would mean the end of her kingdom and everyone she cares about.