Abby is struggling between reality and the world that has been driving her insane. Her not being accountable for this makes more sense than the other deaths in Salem. I am, of course, assuming Ben is done. Chad will be rife with grief for her getting to this point. He has known Ben is in her head but he loves her to the deepest part of his heart. Ben was unsalvageable. I thought when he said they were connected he was going to bring Thomas into that. It didn't appear he did or Abby told him Thomas is really Chad's.