First Rider's Call (Green Rider, Book 2) by Kristen Britain
Rating:This is the sequel to Green Rider. The book is pretty good, but it seemed a little more violent than the first. Overall I thought it was a good read, but it wasn't a quick read. The way the books ends leaves a lot of unanswered questions. It seems as though the book was not written to stand on its own, but as a part of a larger story. If you liked the first you'll probably like this one.
Mornhavon the Black is stirring within his prison and as his power grows odd things begin happening with magic. Dark creatures have arisen and people are afraid. Karigan G'ladheon is a green rider with the magical ability to become invisible. When her ability begins to behave strangely and even fail at times, she knows that something must be done. Karigan will need not only her ability and the help of friends, but will have to reach across time to enlist the aid of the first green rider in order to stop Mornhavon's evil.