I have my third conjecture for this drama:
Wasn't the mother creating something when the infected came to kill her? I suspect that ultimately, the doctors are going to get a hint from the chemicals on the table and find out what was the substance that the mother hid in the drawer. Maybe it can help Ji Sung become human!
All conjectures stem from my own thoughts - if you would like to repost this, please give full credit.
- Another one