Connect the Dots (Yuying)

In a sense, Yuying's universe has already met with the strange ancient Chinese universe that she'd woken up in.

She, along with the person who'd been in her body while she'd been away, served as the point of contact between the two worlds. 

Yuying starts to wonder about just who this person could be as she continues to stare up blankly at the lines along either side of the ceiling.

She thinks about what Jiawen, Tian Gou, and Professor Williams had told her and attempts to mentally draw a picture of how this person could look like based on their accounts.

Yuying thinks about what Jiawen had said.

/Well, for starters, Sarah from a few doors down claimed that you were trying to wash your hands in the toilet bowl. I didn't see it for myself, but that's what she said.../

Apparently, the person who'd been in Yuying's body had attempted to wash their hands in the toilet bowl of all things that they could've washed their hands with.