Didn't you do it?
The thing in your pocket can't fly away like that because of its location, right?
I'm sure he was holding it when writing the postcard or putting it on the table.
I think it came out like that because it collided with a car and flew away.
Didn't Dohee prepare to eat poison after writing the postcard?
Let me guess...
ㅠㅠ
The sight of Guwon running towards Dohee was so sad that I almost burst into tears.