Drums of autumn (outlander book 4)

Claire Fraser, reunited with her husband Jamie, face a new life in the American colonies after being shipwrecked on the Georgia coastline. Meanwhile Brianna Randall, safely ensconced in the 20th century and now essentially orphaned by her mother's departure to the past, struggles to accept her loss and satisfy her curiosity about a father she has never met, only to discover a tragic piece of "history" that threatens her parents' happiness in the 18th century. This discovery sends Brianna back through time on a mission to save her parents, and Roger Wakefield, the young Oxford historian captivated both by Claire's impossible story and Brianna's engaging presence, feels compelled to go after her through the stones.