The Seeker and the Shade by Ellen Osborne

Inexperienced but determined, Connie is desperate to become a caster to save her village from the deadly Shade. Arrogant and privileged, Jasper is everything she detests. He intends to become a seeker like his father before him, and he has no time for a no-hoper like Connie. Thrown together at Blackwood, Connie and Jasper are pledged to each other as caster and seeker, learning to light the oath lamps and conquer the Shade, as well as their mutual dislike... but could the undeniable connection that flickers between them become an unbreakable bond? Their lives depend on it, for the vows are failing, the Shade is advancing and only those with the strongest conviction will survive.