Cora and Hook are in Storybrooke. It is possible that they are going to kidnap Henry. Cora will probably have a bone to pick with Emma for besting her on the beach; she wants to prove to Emma that love is a weakness. Hook will probably play both sides. Additionally with Cora in the picture that would give King George some added support in his arsenal since Cora and Regina would be preoccupied with each other where he could go after the Charmings.