Geillis wants those three sapphires in particular because apparently there's a prophecy that states that when a seer holds all three, he/she will be able to foretell when the new Scottish king will rise.
Starz's version of the prophecy is, "A new king will rise in Scotland upon the death of a child that is 200 years old on the day of its birth." With the knowledge that Brianna was conceived in 1746 but born in 1948, Geillis decides to travel back to the future to murder Brianna.
William Buccleigh was born in December 1743 to Geillis Duncan, an accused witch and murderer. As she was condemned to die, William was taken to be raised by another family who had recently lost an infant, and they gave him the dead child's name, a common practice at the time.
Geillis and Dougal's son was adopted by a family in Cranesmuir, and he grow up to be William Buccleigh MacKenzie, also known as Buck.
In Outlander Season 3, Episode 13, Geillis gives Claire a quick rundown of the events that happened. Geillis gave birth to the baby, who was given to William John and Sarah MacKenzie, the couple whose baby had been “taken by the faeries.” After that Dougal was able to smuggle her out.
Geillis and Dougal's son is William Buccleigh MacKenzie. We've met him in both the books and the show. He's also known as Buck, and Graham McTavish played the role in the fifth season of the series.
Roger is a descendant of Geillis and Dougal's son. Roger has Geillis's green eyes and inherited her ability to pass through the stones. He meets her in 1739, having traveled through time in search of his son, Jem.
“He's about 25,” Gabaldon said. It's an interesting response. If you're up to date on the series, then you know that Jamie is not dead at the age of 25.
Finally we discover how she survived: Because she was pregnant, they didn't burn her straight away. Dougal, bless his foolish soul, came to get the baby and helped her escape.
He was the illegitimate son of Dougal MacKenzie and Geillis Duncan.
“I curse you. I curse you with knowledge, Jack Randall. I give you the hour of your death. Jonathan Wolverton Randall, Born Sept 3rd, 1705, dies…” she whispers in his ear, and suddenly he knows that she's telling him the truth.
Geillis' Duncan's Death in the Books
Of course, Claire doesn't know that yet (in the books or the series). Instead, she simply gets a vague feeling of being connected to the bones, and that the woman didn't want to die when she did.
Does Claire know? Yes, Jamie told her after they finally reunite in the Print Shop in Edinburgh.
Let's learn about the disease that robbed Jocasta Cameron of her eyesight: Glaucoma. Yep, that's the one. Glaucoma (glaw-koh-muh), is a word derived from the Greek glaukommatos meaning “gray-eyed.”
Outlander Author Diana Gabaldon Explains Why Jamie Calls Claire "Sassenach" It actually means something less-than-kind.
Claire is about four years older than Jamie in Outlander
She was born on Oct. 20, 1918. It was 1945 when she fell through the stones, and she would have been turning 27 that year. In the show, she has already turned 27 by the time she falls through the stones as the series is set in October rather than May at first.
It's kind of too early for Claire to discover Geillis, and in the books by the time they meet, Claire already knows that Mrs. Abernathy is responsible for Ian (and other boys) being kidnapped. Also, Geillis has definitely aged and is suffering from syphilis, so there's that as well.
Confession of Geillis Duncan (folio A4r)
Geillis Duncan was tortured with the pilliwinkes on her fingers and by binding or winching her head with a cord or roape.
Dougal kept a close eye on the two women during their time at Castle Leoch. On whether he thought Claire and Geillis were time travellers, actor Graham, 61, explained: “Yes, I do.”
Because yes, Claire and Lord John end up married in book seven, and yes, they drunkenly (and full of grief for the loss of Jamie, whom they both love with all of their heart) consummate that marriage. And then Jamie shows up alive and well!
How old is Jaime in season 1 when he and Claire married? He's 22.
We catch up with her 20 years later when Claire heads back through the stones and ends up in Jamaica while searching for Young Ian. This is when Geillis learns that there is a way to travel again. She also finds out about Brianna. While younger Geillis had met Brianna, she would have had no idea who Brianna was.
Claire's face was turned away from the camera and she didn't use the surname Randall. Geillis suspected this was the same woman (or at least, another time traveler), but had to play things carefully to get the information out. Eventually, Geillis learns the full truth about Claire.
In Scotland in 1968, Claire tells Roger Wakefield that Geillis Duncan was his ancestor and that she was burned as a witch in 1743.