Motayne, Maya. Forgery of magic #1

Series information from Goodreads.com

Finn Voy is a faceshifter who got caught in a compromising position and now must steal a royal treasure or face the consequence of being stripped of her magic -- her only disguise and protection -- forever. When she runs into Alfehr, Crown Prince only because his perfect older brother was murdered, the two accidentally unleash an apocalyptic power

"A faceless thief. A desperate prince. A darkness unleashed"--Dust jacket

Map on endpages