So I’m assuming that Michael is Bae and August went to go find in ‘We are Both’ to bring him to Storybrooke. Perhaps Rumple sent him and that’s why we see Rumple standing at the border at the end of the episode.
Part of me really likes this theory and can see the episode ending with Bae opening his apartment door and finding August there. But August is wooden again – would he be able to move around, unnoticed, in New York? Really do think he probably sent the postcard and that’s where he was when his papa came to this room…