"Bao'er, get back here!" She didn't heed Han Sen's call, but she did turn around and wave at him. This prompted him to follow, despite the sirens in his head. When he caught up with her, she had crawled even further forward.
"Don't go in there!" Moment Queen shouted. If Han Sen died, she did, too. There was nothing for her to gain in her master's untimely death.
Han Sen returned Moment Queen to the Sea of Soul and continued chasing after Bao'er.
He would have put his foot down and stopped her if Bao'er was an ordinary baby. But her appearance obviously hid her true maturity and knowledge. She wouldn't have crawled into the castle like she was, if there was nothing of value to be found there.
When they got inside, there were a variety of different passages. The variety of passages didn't slow Bao'er down, though. As if she knew the way to go, she kept on crawling without a single pause to collect her bearings.