But Belle (Emilie de Ravin) turns out to be far from Rumple's weakness, as her strength and support, as well as her undying faith in him make him stronger than he would be on his own. Hook ransacks the pawn shop while Gold is rescuing Belle from the library, and steals Baelfire's shawl, the only item he still has from his son. It is an object needed to make his spell work and allow him to travel beyond the Storybrooke border. It is Belle's adventurous spirit and resourcefulness (as evidenced as well in her parallel story in Fairytale Land) that leads to the shawl's recovery.
In Fairytale Land Belle meets Mulan and they set out to slay a beast called the Yaoguai, who has been ravaging Mulan's land. But the beast is no beast, it is the cursed Prince Philip, and it is Belle's kindness that breaks the curse.
During this adventure, which occurs after she leaves Rumple's castle, but before Regina takes her captive, Belle realizes how much she wants to fight for Rumple's redemption and love. "I will never stop fighting for him," she yells at Regina, who takes Belle prisoner just as she sets out to return to Rumple.
And she never has, even after she learns that Milah hadn't just died, but that Rumple had torn her heart out and crushed it. Belle hits the nail straight on when she explains why she refuses to give up on him. "His heart is true," she tells Captain Hook. "Yours is rotten."
Above anything, I think, Belle is drawn to the love that Rumple feels for his son. I think she has take by it from the moment in last season's "Skin Deep" when she sees the emotions Baelfire's memory evoke in Rumple. A man who loves his son that deeply cannot be a beast or a monster.
No one is more astonished at Belle's love than is our Rumple. Even after all he's done, all she's learned his done, still she doesn't give up. Still she stays by his side, refusing to give up on him. "When you find something worth fighting for you never give up," she explains simply. It struck me in that moment just how similar Belle and Rumple are in a way. Her words could have as easily emerged from Rumple's lips about his son. But now, it appears at the end of the episode, how much those words might also apply to Rumple's relationship with his beloved Belle.