Once Upon a Time may have been renewed for a seventh season, but it's safe to say whatever comes next will look nothing like the show we've come to know and love. It might, however, feel pretty similar.
After giving pretty much everyone a happy ending/beginning and only having to kill off the Black Fairy, OUAT essentially started the series from the beginning, but with a twist. Henry is now an adult (played by The Walking Dead's Andrew J. West, a dead ringer for Jared Gilmore) who has forgotten that fairy tales are real, and it's up to his daughter (played by Alison Fernandez) to convince him of the truth.
Throughout the episode, without knowing who we were watching, we saw Henry send his daughter away with the storybook and then having some evil thing burst through his door. When his daughter returned, it looked like their house had exploded. Later, we saw her riding a monorail through Seattle to find her dad. That's how season six (and the show as we know it) ended, and honestly it could make for a pretty cool season seven.