Explanations, please?

I haven't read ahead or anything but I'm pretty sure he filled the bottle so he could time how long it took him to go get cigarettes... that's just my guess. ;/

He made a timer by poking a tiny hole in the bottom of the milk carton and filling it with water. The water drips slowly down into the water bottle. By setting it up when Sungho leaves and then checking how full the water bottle is when Sungho comes back, he can get a sense of time, which will help him prevent another situation where Sungho suddenly walks in on him while he's up to something.

I think he put some medicine or something in it and he is worried because if the other guy will notice the broken chain or the books in the pillow he will know that the he is faking to remember (sorry for my english)

Ah, yeah. I suppose that the time it took informs him on how far away from civilization he is? Everything else is so strange. His memories are jumbled up and I can't understand them. This story will be the death of me, I swear.

That's what I originally thought, but wasn't so sure. Thank you!

That helps me a lot, thank you! Also, it's good, don't worry.

It's definitely a timer. The water bottle had these grooves which served as the markers. He said something like 2 marks so it took 2 marks for Sungho to come back from his trip. In chapter 23, he read the diary when Sungho left and as soon as the bottle reached the second mark, he put the diary away and Sungho walked in shortly after

Ah, thank you!

tNah ur English is fine. But I thouhgt he put medicine in it too. Though the captor noticed the pills and said it was a pain killer......not quite sure what that would do if he drank it unless it was a VERY nice pain killer lol. Maybe its a way for him to tell the time by how long it takes to dissolve and as a bonus if the captor drinks it and hes put multiple pills in there it knocks him out?

No. What you saw were water droplets dropping down from the milk carton. He didn't put painkillers in it. He even said that there were nothing to drug Sungho

I said it could be an added bonus. Not that it is one. And that it could be used as another way to tell time.

Well from what I see, the bottle serve as timer. If the kidnapper knows he's been up to something, wouldn't that bring more danger to him? He might be locked in the darkness all over again and maybe not gonna go out for go knows how long. It's the same as the chain, the book he keep inside the pillow and the that he wrecked the drawer. If any of it was to discovered, he would be done totally.