I really don’t think it’s Henry’s heart, or maybe Pan thinks it is, I don’t know. All I know is that PP wasn’t actually sure Henry had it himself, because he tested him. Henry passed the test that’s true, but it’s easy for Henry to believe in magic, there’s no struggle at all for him there. It doesn’t make a good story.
Whereas for Emma, belief is hugely difficult in nearly every way for her. Believing would make her the Truest Believer in every sense.
@Rumplesgirl – I don’t think that both she AND Henry could have the HoTTB because it says “believer” not “believers” indicating that there is only one.
I’m sure i’ll be amending this theory in the weeks to come but as it stands right now I think it’s Emma’s heart that Pan wants/needs, and who knows Pan himself may not know it yet.
Keeper of Captain Swan's first kiss