A satisfying conclusion to this time travel trilogy. I'm not a lover of romance (which this is at heart), but I love the intricate complications of time travel and all the fascinating historic details. More than once I had to go to the Internet to look up the history behind the story. Higley has created her own system where some travelers can change history, but for others as soon as they return to their present, all they did in the past is forgotten and undone. Forgotten and undone prevents the unintended ripple affects of change, but there are times when undoing the changes would mean losing the love of your life.
There are references to a Higher Power potentially behind their abilities, but no over references to faith or Christ. The Epilogue, a letter from Sahara to her daughter, gets a bit preachy and would benefit from tightening.
I hope Higley writes some more stories with this theme. There was talk of the benefits of advanced medical care in the twenty-first century. I found myself thinking that once Persia is an adult, Alex and Renae could return to their proper time and live longer to return to vacations in the past with their daughters and grandchildren. And there are lots of new possibilities as time travel powers get focused on future generations. The one thing I had trouble with in Higley's time travel system is that the travelers always appeared in appropriate dress down to shaved heads for male slaves in ancient Egypt.