I have a strong suspicion.
Ann tells Connor that the garden and tree where there was the swing makes her feel odd and troubled; she doesn’t know what causes this feeling, but she is afraid that there is something that she might not want to remember. So now I wonder if this feeling Ann gets has something to do with her father. She has never heard from him again, and she has vague memories when he left her and her mother. So since Ann seems so out of sorts, I have the idea that she might have seen something as a child. What if her father was killed in the garden. What if Phoebe killed him and Ann witnessed it? Maybe that is the reason why Phoebe kept her daughter at arm’s length for years because she was afraid Ann did remember. If this is true, I am curious to know what could possibly have happened to result in this way. Phoebe seems to be the kind of person who wouldn’t harm a fly, so I believe that there must have been a reason to send her over the edge.
As for the research in the past, we get to know what happened to William. He was wounded, and when he came to, he realized that he didn’t even remember his own name. That was in France, and a peasant woman took him in. Shortly afterwards the authorities arrested him for desertion, and when they realized what his condition was, they sent him to a hospital in Devon. It is in the hospital that Walter’s mother is working as a volunteer, and she recognizes the paintings that William makes from memory. So she writes to Hester, who is hopeful that it can be William. It is clear that she is disappointed when William tells her that he doesn’t remember her or anything much. So that makes me think that definitely something happened between them while he was on leave. Did they really become intimate? Will Hester tell him about what happened between the two of them? Or will it be too awkward, so she will keep quiet, unable to express her feelings?