On v0.13, there is a new quest leading to Cynthia event, you need to spend 30 days in-game and then trigger the event after you wake up. You will find Serena after finishing this event
You mean on v0.13 right? Because There is no Serena nor Cynthia in v0.11. I know it's a small mistake I just want to correct it for the people who go into the comments for advice on things.
