Book three of The Chalcedony Chronicles, a paranormal/time travel romance series.
Mari's past and present are all mixed together. To start, she finds herself trapped in the past while her friends from the past are now all in the future. She wants to go home, but Logan Jones has different plans - which include Mari. He might say he wants her, but soon she realizes that there's something more behind it. To save everyone in the future, Mari strikes a deal. She must give up Seth and agree to date Logan. In return, he'll teach her to how to help her friends and family. Only, letting go of Seth, and falling for Logan aren't easy feats. If Mari can't figure out how to do so, she might lose everyone she loves.