Blackveil by Kristen Britain
Karrigan is back in the the fourth book of the Green Rider's Series by Britain. This time she is one of the people chosen by the King to accompany the elves back to the forest Blackveil to find out how it has changed in the centuries shut behind the wall. In a hostile land, Karrigan must her her ability to travel through time to prevent a hostile force from gaining control of the sleepers and corrupting them beyond repair.
Considered to be high fantasy this series remains fairly strong. I read the first four novels so that I could read the fifth novel which comes out this year.