him to Fraser's Ridge. John had the measles and Claire sent William and Jamie away while he was contagious. The six days William spent with Jamie alone, triggered something. He asked him if he used to be a groomer named Mac? He said yes. William then asked him, if he knew him as a child, why did he pretend not to when Lord John introduced them? I don't recall Jamie's answer. But then William recalled the day Jamie left and he ran after him, calling his name.
William: The day you left Helwater. I called to you and ran to you, but you never turned back. Why? Why didn't you look back at me?
Jamie: I wanted to. I didn't look back because I didn't want to give you false hope. I never expected to see you again.
The day Lord John and William left Fraser's Ridge--William looked back at Jamie...this time he stepped forward and William looked at him with admiration. So it was a callback to what happened when he was 6 years old and that gave Jamie hope.
