As Emma suspected, Captain Hook will run right back to Cora after escaping from Emma’s trap.
Mr. Gold and Regina will be putting David’s life at risk, apparently with his permission, so that he can give Mary Margaret “vital information” on how to find the portal to Storybrooke.
Cora wants out. Cora is doing everything in her power to get the magic compass back from Emma, Mary Margaret, Aurora, and Mulan.
Henry falls under the sleeping spell, and sees Aurora in his dream. It seems, from this preview, that they intend on working together to find a way for Mary Margaret and Emma to get back to Storybrooke.
Cora releases zombies. From this promo, it looks as though Cora has the dark magic capabilities to raise the dead ogres from the battlefield, and send them off to kill her enemies.