A. House With Good Bones by T. Kingfisher

"Mom seems off."

Her brother's words echo in Sam Montgomery's ear as she turns onto the quiet North Carolina street where their mother lives alone.

She brushes the thought away as she climbs the front steps. Sam's excited for this rare extended visit, and looking forward to nights with just the two of them, drinking boxed wine, watching murder mystery shows, and guessing who the killer is long before the characters figure it out.