There once lived a proud princess. One night her heart was stolen by a clever thief. He left his heart in place of hers, but eventually the princess began to grow sick. After a time she went to the thief and demanded her heart back. The thief broke her heart and returned to her a single piece. The princess cradled the piece and returned to her kingdom, vowing to keep the thief's heart until hers was back in one piece. Over time, her heart was returned to her, piece by piece, until the pieces stopped coming: though her heart was not complete.
The princess later met a charming prince, but he became unnerved by the thief's heart. So the princess bagged it up and locked it away. Still, the prince could always hear the heart's beating where ever he went. He began to see visions of the thief, and he could hear the thief's voice in his head. Certainly the thief was a dark and dangerous wizard.
The princess gathered up the thief's heart and set off to see the thief for the last time. She met with him in a dark place. He was afraid she would see a monster. Without a heart of his own, he had changed: just as she had grown sick without her own heart. When she pulled the thief's heart from her bag, it shattered and crumbled: a darkness seized her. Without proper care, it had grown weak. Ashamed, she poured the heart back into the bag, dropped it to the ground and ran. The thief still held a piece of her heart.
She ran from the dark place and returned to her prince. They married and traded pieces of their hearts, but no longer proud, and no longer a princess: the darkness never left her.