I'm thinking now that Abe was horrified in the previous chapter because maybe that power that suddenly appeared in Fay's hand was like Andromeda? The ancient powers, the ancient grief Abe showed and then Andromeda's pain. And we know once that Abe and Andromeda were lovers. And basically Fay is like the medium (her body that was chosen by Andromeda to inhabit). Makes me wonder why she was chosen, if that was the case at all and why she's special for that.