Thirty year old Edwin adopts Deanna aged thirteen and destroys all her hopes and dreams when she is eighteen; then tries to kill her when she is twenty. She hides out in the home of aging Park Ranger Eli. Deanna makes a promise to Eli that she doesn't want to keep but he shares two secrets with her that forces her to keep the promise.
Before the promise comes due Deanna is studying with a top botanist, Graham Whitmore, and falling in love with him when Edwin shows up. Eli, Deanna, and Graham deal with Edwin who threatens to disrupt all their lives.
Deanna is on the verge of getting a degree and Graham expects her to become his assistant on a major expedition and she wants to go so very much. But the promise falls due and she has to give up her studies and Graham. It is then she learns something about herself that pushes her over the edge. Graham doesn't give up on her and works long and hard to find out why she tried to close him out and what shut her mind into a safe place within itself.