While aboard the Glorianna, Roger encounters Morag MacKenzie and realizes she’s his four-times-great grandmother and her son his three-times-great grandfather. He protects them from the Captain: Stephen Bonnet. While coming back from warning Murtagh about Governor Tryon’s intentions during the Battle of Alamance, Roger comes across Morag MacKenzie. He tries to warn her but is confronted by her husband (Roger’s 4x great grandfather) Buck MacKenzie who is also the son of Geillis Duncan and Dougal MacKenzie. Buck beats and ties up Roger, leaving him to be thought a Regulator. While Brianna and Roger are living in the future at Lallybroch, Jem and Mandy believe there is a Nucklavee that keeps peering in the window. Roger catches a glimpse of someone and goes after then finding Buck MacKenzie. Buck tells Roger and Bree that after Alamance, he and his family went back to Scotland in hopes of finding work. They were on their way to Inverness when they heard a strange noise (he went through Craigh na Dun). He went to investigate and woke up here. He wandered around, discovering cars, and eventually saw Roger and followed him back to Lallybroch. But because of their previous interactions (namely getting Roger hanged) he kept his distance but apparently told the children he was a Nucklavee and had them bring him food. They explain things to Buck who is stunned. When Jem is kidnapped, Buck joins Roger on his journey through the stones to find Jem. The two find Roger's father instead. Buck and the MacKenzie family go their separate ways but Buck joins everyone on the Ridge. Buck saves Jamie's life when Cunningham tries to take it. Buck tells Roger, he killed Rob Cameron in the future when he discovered Rob was preparing to time travel. Source: In the Forest, Send for the Devil, Muskets, Liberty, and Sauerkraut, A Practical Guide for Time-Travelers, Where the Waters Meet, The Ballad of Roger Mac, Down the Rabbit Hole