Ian accompanies his aunt and uncle to Charleston in the Royal Colony of South Carolina, where he is to take ship home to Scotland. To Ian's delight—and his uncle's dismay—the ship has already set sail, and so Ian continues on with Jamie and Claire (and with his new furry companion, Rollo) to Cross Creek in North Carolina, where his great-aunt Jocasta owns the River Run plantation. The group travels up the Cape Fear, and arrives a bit worse for wear after a run-in with pirates, but Young Ian remains his eager, cheerful self.
After Jamie and Claire resolve to help a slave escape to join an Indian tribe in the mountains, Ian parts company with them to meet the Indians with John Quincy Myers, while Jamie and Claire travel further to scope out the land for settling. Eventually Ian rejoins them and helps his uncle build the first cabin on his land, and the three spend their first winter in the mountains together. Ian maintains a friendly relationship with several nearby Indians, often joining them on hunting expeditions with his dog, Rollo.
While the Frasers' cabin entertains two unexpected guests in the forms of Lord John Grey and his stepson, William, Claire treats one of Ian's Indian acquaintances, who suffers and eventually fatally succumbs to the measles. Ian himself contracts the disease, as does Lord John, though both recover under Claire's ministrations. It is also during this episode that Ian recognizes young William's resemblance to Jamie.
Nearly a year later, the unexpected arrival of Jamie and Claire's daughter, Brianna, brings excitement to the Ridge, and she and Ian become fast friends as new-found cousins. Ian also grows close with Lizzie, Brianna's handmaid from Scotland, and when Lizzie recognizes a man called MacKenzie, who is making his way up the mountain, she confides to Ian that the man assaulted Brianna in Wilmington. Not wishing to involve Brianna and risk upsetting her, Ian and Jamie meet MacKenzie before he can reach the Frasers' cabin and beat him to a pulp, before handing him off to some of Ian's Indian friends, who will then sell MacKenzie to the Iroquois.
When it becomes apparent to the Frasers that Brianna is pregnant, with no word of her man, Roger Wakefield, Ian awkwardly proposes marriage to his cousin, offering himself as both a husband and father to protect Brianna and her child. Brianna refuses, but appreciates the gesture, however misguided and old-fashioned she finds it to be. About a month after disposing of MacKenzie, Brianna sketches a portrait of Roger, and to Jamie and Ian's horror, they realize that "MacKenzie" is in fact the same man as the Roger Wakefield they'd been sending word out for. The family thus hastily travels down the mountain to River Run, where Brianna will stay while Jamie, Claire and Ian set out to rescue Roger.
They eventually find Roger in the custody of the Mohawk in a village called Snaketown, where Ian quickly becomes friendly with a pretty girl called Wakyo'teyehsnonhsa (Works With Her Hands), and whom Ian nicknames Emily. After witnessing the harrowing deaths of a Jesuit priest and his Mohawk lover, negotiations for Roger's release are complicated by the matter of a Mohawk who died. Ian takes the matter into his own hands, and chooses to become a Mohawk to replace the dead man, leaving Jamie and Roger free to leave with Claire to return to Brianna.
In October, the Frasers receive a letter from Ian, who informs them that his wife, Emily, is carrying his child, and reaffirms his promise that he'll never forget his family.