Spoilers ahead for the Outlander Season 4 finale. Outlander had a lot of ground to cover, quite literally, when it came to reuniting Brianna and Roger in the season finale. But the drama for the Frasers is far from over now that Jamie has been tasked with killing Murtagh. Claire warned Jamie that if he took the land from Governor Tryon that there would be trouble down the road, but at the time, she was thinking of the impending American Revolution. They didn't realize how much Jamie's British allegiance would directly affect their family.
At the beginning of the Jan. 27 episode, Jamie, Claire, and Ian are able to strike a deal with the Mohawk for Roger's safety — however, it means Ian must surrender himself in Roger's place. Because he's still processing the fact that Brianna is most likely pregnant with Stephen Bonnet's child, Roger initially declines to return to Brianna with Jamie and Claire. But he eventually comes to his senses (took him long enough), and it seems the family will all happily return to Fraser's Ridge, including Bree's new baby. That is, until Jamie gets a message from the governor that he's supposed to create a militia to fight the regulators — and capture and kill Murtagh.
Before Season 4, Jamie hadn't seen his godfather since they were both imprisoned at Ardsmuir — nearly two decades ago. This is a major departure from the books (spoilers) since Murtagh died at the Battle of Culloden in Voyager. In the Starz series, Murtagh survived to rebel against the British again, and while he'll be on the right side of history this time, he may not live to see the American Revolution due to Jamie's orders.
Season 5 of the TV show will follow Diana Gabaldon's fifth book, The Fiery Cross. As Gabaldon's website explains, The Fiery Cross takes place during North Carolina's War of the Regulation, a rebellion against the real-life Royal Governor William Tryon that lasted from about 1766 to 1771. The synopsis for the book notes that in order to keep his land on Fraser's Ridge, Jamie must "walk a delicate tight-rope between the pressing urgency of the rebellion and the increasingly unsteady but still dangerously powerful government."
In Outlander Season 5 (which doesn't have a premiere date yet), Jamie will still be facing this War of Regulation, but with some added stakes. The British soldiers who delivered Jamie's orders don't seem to realize that Murtagh is at River Run, so that will buy Jamie some time to devise a plan. But is it possible that Jamie will have to kill Murtagh to save the rest of his family? Could he even bring himself to do that?
Jamie could take issue with the fact that Murtagh has entered a relationship with his Aunt Jocasta — especially since Murtagh's love for Jamie's mom (Jocasta's sister) is what connected them in the first place. But while Jamie raises an eyebrow at Murtagh and Jocasta in "Man of Worth," that's certainly not enough to make Jamie comfortable with killing him. Instead, it seems far more likely that they will come up with some elaborate plan to trick Governor Tryon into believing Murtagh has been captured and killed. But that will inevitably lead to Murtagh either having to flee the Carolinas — or ending up dead by some other means.
Even though he knows he'll have to eventually betray the British once the American Revolution begins in earnest, you can expect that Jamie will form a militia in Season 5. How he'll handle the Murtagh dilemma, however, is what's uncharted territory. Considering his fate in the books, Murtagh is already living on borrowed time, so take the break between Seasons 4 and 5 to prepare yourself to say goodbye to him one way or another.