Drums of Autumn - Diana Gabaldon

It began in Scotland, at an ancient stone circle.
There, a doorway, open to a select few, leads into the past--or the grave.
Claire Randall survived the extraordinary passage, not once buy twice.
Her first trip swept her into the arms of Jamie Fraser, an eighteenth-century Scot whose love for her became legend--a tale of tragic passion that ended with her return to the present to bear his child.
Her second journey, two decades later, brought them together again in frontier America.
But Claire had left someone behind in the twentieth century.
Their daughter Brianna...

Now, Brianna has made a disturbing discovery that sends her to the stone circle and a terrifying leap into the unknown.
In search of her mother and the father she has never met, she is risking her own future to try to change history...and to save their lives.
But as Brianna plunges into an uncharted wilderness, a heartbreaking encounter may strand her forever in the past...or root her in the place she should be, where her heart and soul belong...