Board Thread:General Discussion/@comment-24674051-20140331041704/@comment-9232373-20140402172624

Hook is probably assisted by Ariel in returning to NY, since she can cross realms.

How Hook knew to come and get Emma is dodgy... he tells MM and David that he got a message AND 1 dose of memory potion from a bird, which is why he thought MM sent it. He tells Emma he only could gather enough ingredients for one dose of memory potion. So, there's already inconsistencies on how he got the potion. One story it's given to him, another he made it himself.

The only person who knew Emma would be in NY is Regina. So perhaps she sent Hook the message, though it is totally possible she just gave that info to MM who then gave it to Hook.

Neal's knowledge was probably told to him by Emma, as I am sure he would ask her why and how she is there.