Let's dive in!

In Storybrooke, Hook tells Mary Margaret and David that he was with them in the Enchanted Forest for a while, but then he left. He says that while sailing, he was sent a message by bird with a note telling him to get Emma because a new curse had happened. It also included the memory potion. Hook had assumed that Snow had sent it, but of course Snow can't remember anything. Leroy/Grumpy shows up and says that Dwarves are disappearing left and right. Emma decides to get everyone's memories back, the first step being to discover who cursed them in the first place.

At the diner, Henry meets David and Mary Margaret. They say they're friends of Emma's from Phoenix. When Regina comes in, Emma pulls her aside and explains what's going on. Regina insists that she is not the one who cursed them all, and she points out that she would never have set up a scenario where Henry doesn't remember her. Little John gets taken, and they figure out it's because he crossed the town line. Hook and David search the woods, along with Robin Hood, while Emma calls a town meeting.

Emma and Regina stage a big fight where it looks like Emma believes Regina made the new curse, just like everyone else does. Later, Emma and Regina meet up, and Regina tries to make more of the memory potion so that everyone can figure out what's going on. Regina fails to succeed, but Emma has a new idea about how to catch the curse-caster. If they pretend they're about to make a memory potion, the guilty party will freak out and try to stop them, thus revealing him or herself. At the diner, Mary Margaret meets the Wicked Witch, whose name is apparently Zelena. Zelena says she was a midwife back in the Enchanted Forest, and agrees to help Mary Margaret with her pregnancy. She seems to have sinister plans for the baby. Leroy comes in to the diner and tells everyone that Regina is making a potion. Zelena goes to the mayor's house to try and destroy it, while Emma and Regina participate in a stake out. Regina asks Emma about Henry's life back in New York. Their conversation is interrupted when they see someone moving in Regina's office. When they go to catch the culprit, however, she vanishes. Regina is stumped, because she used blood magic on the room, and nobody should have been able to leave.

Hook, David, and Robin find Little John injured in the woods. At the doctor's office, he turns into a flying monkey! They tell Emma and the others this news, and Emma introduces Henry to Regina. Flying monkeys and green smoke? The group is smart enough to put together that this means the Wicked Witch! We see Zelena go down into a dungeon and speak briefly with Rumplestiltskin, who she is holding as a prisoner.

In the Forbidden Forest, we see the group continue to travel together. A flying monkey tries to attack them, and Roland, Robin's son, is in danger. Regina uses magic to turn the monkey into a stuffed animal, and she gives it to Roland. Regina decides to get into the castle by herself to confront the Wicked Witch. Robin tags along, saying that she'll need extra help. When Regina gets to the underground door leading to the crypt, she is startled to see that it's open, even though blood magic should have made that impossible. Regina reveals that she's planning on using a sleeping potion on herself so that she'll be cast in an enchanted sleep. That way, the only way she'll wake up again is if her only true love (Henry) awakens her. That's the only reason she'd want to wake up anyway.

Before Regina can take the potion, Zelena shows up. It turns out she's Regina's half-sister. Zelena is angry that Cora gave Regina everything and cast Zelena aside, so she vows revenge. Regina says that she has something new to live for now - someone to destroy.

Oh boy. There's always so much going on in this show. It takes a long time to write plot summaries. There were a lot of great things going on here. I only had a few problems...

It seems as if everyone who wants to make a potion in this show can do so with no problem. Now, Regina is failing to make a memory potion? What's that about? It seems like yet another all-too-convenient excuse to keep Henry without his memories.

People turning into flying monkeys? My friend is calling them "were-monkeys" now, and that seems an apt enough description. I'm not sure what I think of this. Once you turn into a monkey, are you automatically loyal to Zelena? She seems too powerful to stop!

The fake-out fight between Emma and Regina was so transparent that I lost respect for everyone who fell for it. That is all.

Oh, and one other nitpick - Mary Margaret is acting like she's never been pregnant before. Didn't she go through all of this stuff while pregnant with Emma? Or did the magic of the Enchanted Forest make the pregnancy less difficult?

And now for some things I really enjoyed:

Regina and Zelena are half-sisters! Yeah, I mean I could have guessed that, but it's still an awesome plot element! I hope we get more of Oz and its mythology.

Rumplestiltskin! It was obvious they were bringing him back... I mean, there were lots of sightings of Robert Carlyle on set, but I'm still so glad to see him! And what a way to reveal him, too!

The difference between old Henry and new Henry. He's still the same kid, but he's a year older and plays lots of video games now. I like how it's affecting the rest of the town to see this kid that they care so much for, and to know that he doesn't know them.

Robin Hood! They're really selling me on his character. I love him. His concern for Little John was really touching, and his adventures with Regina point towards a romance in the near future!

Can't wait for next time.