SPOILER ALERT! If you have not read until book 7, An Echo in the Bone, don't read this.
Apart from all the very thick books in the Outlander series, Diana Gabaldon has also written shorter novels, which give us the opportunity to further follow some of the characters that inhabit her books. Most of them follow Lord John Grey. However, in this one it is Joan MacKimmie, Marsali's younger sister, that we follow on her way to become a nun in France. Michael Murray, young Ian's elder brother, accompany her there. He is working in the family wine business, and is in a mourning mood since both his wife and father died recently.
Having arrived in Paris, Comte St. Germain has returned from somewhere in history. His aim this time is to find the source for youth. He is looking for the apothecary Raymond, but when he finally meets him, Raymond is not what he used to be. Does he not look younger? How come he can come and disappear in a cloud of dust? Has he found the source?
We meet again some of the characters from Dragonfly in Amber; Comte St. Germain, Mother Hildegarde, and a few more interesting persons. What is then the space between? Well, not surprisingly it deals with the 'other' world, if it exists. A time travelling space? A space where you can keep your youth? Literature is full of books, playing with the idea of eternal life, being young forever.
Obviously, it is teasing people's imagination. Just look at all the popular vampire books, films and TV-series. Personally, I think that it is not as nice as you think. Here we are not dealing with vampires, but with persons who still sees the eternal youth as something achievable.
Diana Gabaldon is a storyteller of great proportions. You get right into the story, and it is difficult to put it down. The description of people, places, actions and historical hints is absolutely fantastic. I just love everything she writes.