The Space Between is a novella originally published in the anthology The Mad Scientist's Guide to World Domination, edited by John Joseph Adams. On October 11, 2012, A Trail of Fire was published in the U.K. as a collection of four of Gabaldon's short stories, including "The Space Between". The U.K. hardcover, as well as the U.K. Kindle edition, are so far the only available editions.
This story deals with Michael Murray – second son of Ian and Jenny Murray – and with Joan MacKimmie, Laoghaire MacKenzie’s second daughter and Marsali’s younger sister. Joan sets off for France, under Michael’s protection, there to take up her vocation as a nun.
Excerpt – “The Space Between” via Diana Gabaldon's website