A princess was playing beside a well. Her golden ball accidentally fell into the well, and a frog offered to fetch it if she would let him live with her. She agreed, he fetched the ball from the well, then she took the ball and ran off, giving the frog the shaft. The frog showed up at the palace anyway, and although the princess wished not to comply, her father reminded her that she must keep her promises. By the end of the night she's had it with the frog, and throws it against her bedroom wall to kill it, but instead the frog turns into a prince. They got married, and probably had kids.