Things I want to point out
1. In the scene where Eun Bi visits the columbarium with a pot inside her crematory plot, I thought that meant that the body cremated had to be Eun Byul. But this is a K-drama, so I really can't be certain that some background stuff did not happen to keep Eun Byul alive and hidden.
2. If Yi An finds out that Eun Bi is acting as Eun Byul, who is currently "dead", he probably will retreat into grief. This was his best friend for 10 years, who he loved. But for sure, he will help Eun Bi find out why Eun Byul was being weird before she ran away.
3. This Soo In person, I believe was a crazy stalker of Eun Byul. Soo In was doing things to taunt Eun Byul, like turning off lights and writing notes and messages to her, but I'm not sure why yet. Hopefully the next episods will have something to reveal about Soo In.
4. The potential of Eun Bi getting revealed right now is high. With So Yeong constantly at her heels, and Eun Bi who is so bad at hiding anything, her real identity is at stake even more now with the reveal that So Yeong was the one who bullied a girl to death.