Claire returns to her own time in Outlander Season 2/Dragonfly in Amber. It starts the 20-year separation, with Claire living a life with Frank Randall. Of course, she has to tell him the truth about everything that happened to her, even if it sounds like a crazy story.
That must mean that Frank’s ancestor, Black Jack Randall, shows up. After all, Frank had spent a long time researching his family tree, and he believed that Black Jack Randall was his direct ancestor. It was only as the story played out in the past that we found out Frank was actually related to Alex Randall.
We can assume that Claire told Frank about the mix-up of paternity. Did she tell him everything else about Black Jack Randall, though?
Frank writes about Black Jack in the Outlander books
When you look at the books, it’s clear that Claire told Frank something. It’s just not clear how much she told him. Bree and Roger come across letters where Frank writes to Reverend Wakefield to stop looking into Black Jack Randall as he’s not the man Frank believed he was.
That doesn’t mean Claire told him about the sadistic, psychopathic nature of the man. It’s possible that Frank stopped looking into him because he found out that the Army officer wasn’t his direct ancestor.
Of course, if that was the case, wouldn’t Frank have mentioned that Alex was the one to look into? That would make sense if Frank was so concerned about tracing back his family tree. It’s almost like he lost interest in his own family tree completely. This could have been due to having another historical project that took over.
We know that Frank knew more about Jamie than he ever let on. It was like he knew Claire and then Bree would head to the past to be with Jamie. Is it possible that he just lost interest in Black Jack Randall because he obsessed over Jamie, instead? Maybe Claire didn’t tell Frank absolutely everything but enough for Frank to realize that he was researching the wrong man.