At the beginning of Outlander, World War II has recently ended. Claire Randall, who was a British combat nurse during the conflict, and her husband, Frank, are on a second honeymoon in Scotland, having been separated long years during the war. While out walking on her own while her husband was working on his history research, Claire comes upon an ancient stone circle. She touches one of the stones, and she is no longer in the 20th Century, but in the 18th. There, she is caught in the middle of the 1745 Jacobite Rising (an effort to put a Stuart back on the throne) against the English. She also meets a young Scottish warrior, James Fraser. She becomes torn between fidelty to a husband she doesn't know if she'll ever see again and a love she never imagined. Many think her a witch, since she cannot get smallpox or cholera, diseases that claim many lives in a world before vaccines; she also knows things a person shouldn't or wouldn't know. To 18th Century Highlanders, witchcraft is the only explanation.
The story picks up twenty years later, in the 20th Century, with Dragonfly in Amber with Claire needing to tell her now-adult daughter, Brianna, about her real father. The story then flashes back to the time Claire & Jamie spent in Paris, attempting to stop what Claire knows to be the end of the Scottish clan system after the Battle of Culloden in 1746.
Voyager brings Claire, now a doctor, and widowed in the 20th Century, back to the 18th Century in search of Jamie, leaving Brianna behind.
In Drums of Autumn, Brianna and her boyfriend, Roger MacKenzie (a historian), discover an old newspaper clipping that tells of the death of her parents. In an attempt to save them, she dares to go back in time through the standing stones. After she leaves, Roger decides to go after her.
Claire, Jamie, Brianna and Roger are in the colony of North Carolina, in the years before the American Revolution in The Fiery Cross. They all know war is coming, but Jamie, having had to swear allegiance to the King of England as a condition of his pardon, must walk a fine line to keep his family safe.
The Revolution is fast approaching in A Breath of Snow and Ashes. Claire and her family know that soon, Jamie must declare himself a Patriot, but he must chose his time wisely. Also, the date of their "death" - the event that brought Brianna to the past - is nearing. Can they avoid this tragedy, too?
If you have an interest in history, you might find this series very interesting. I likely know a lot more about history than the average person, and I learned things reading these books I had never known before: while I knew of the troubled history between England and Scotland, I was completely unaware of the Jacobite uprisings in 1715 and 1745; the Stuart would-be king, the Bonnie Prince Charles, had found refuge in the French (Catholic) court; I had never heard of the War of the Regulation - which took place in North Carolina - and the Battle of Alamance.
I have enjoyed all of the Outlander series. The books have made me both laugh and cry, and I have a hard time putting them down - even when I know I will pay for it the next morning when the alarm clock goes off... Claire (and Brianna) are stronger, intelligent women who take their 20th Century attitudes with them to the past. Jamie is a man most any woman would love to have fall in love with her (and she with him): he is a good man, to whom honor is important, in addition to the fact he is a very manly - tall, broad-shoulders, red-haired, defends what is his (e.g. - his family) and who doesn't love a Scottish accent ;-)
I will say these books won't be everyone's cup of tea. These books are hard to classify: they aren't strictly romance novels, they aren't strictly "fantasy" and they aren't strictly historical fiction. The romance threads are very *ahem* "descriptive". The stories of battles and their aftermath can be very graphic. Gabaldon has even addressed the issue of "post traumatic stress" through some of her characters - survivors of bloody battles or violent rape. The Library Journal review posted at B&N for A Breath of Snow and Ashes says "Anyone who has gotten this far in Gabaldon's popular "Outlander" saga knows to expect loads of steamy sex, kidnappings, medical miracles, and gritty period details."
Of the related books (listed below), I have only read Lord John and the Private Matter. I didn't like this one as much as the others. Lord John Grey is a key figure in the Outlander series, but I missed Claire and Jamie. I might give the Lord John series another try, though.
The Outlander Series, in order of publication:
Dragonfly in Amber
Drums of Autumn
The Fiery Cross
A Breath of Snow and Ashes
The Outlandish Companion
Lord John and the Private Matter
Lord John and the Brotherhood of the Blade
Lord John and the Hands of the Devil