The ShadowHunter (Witch Bound, Book 2) - Opal Reyne

When her younger sister is stolen in the dark of night, Valerie infiltrates the northern kingdom to rescue her. Parading around as a human and hiding her Witch scent, she doesn’t realise she’s stepped onto a Dragon’s hunting ground—or that the Dragon has settled his lustful sights on her. She only wanted to save her sister, but she can’t resist the way he sets her heart on fire.