@ZdrytchX
I used https://pubchem.ncbi.nlm.nih.gov/#draw=true But there are others like https://chem-space.com/search or https://www.sigmaaldrich.com/catalog/search/substructure/SubstructureSearchPage
@ZdrytchX It seems like he is taking larger molecules and cutting parts out. One looks like Gemcitabine and another is https://pubchem.ncbi.nlm.nih.gov/compound/117882386#section=2D-Structure At least that's what I got from my reverse search before I gave up.
@NinjaGoemon As a guess, she was distracted and slipped down the stairs, just as it showed. Her half-asleep state was sometime later.
Beyond that, I forget what happened here.
His reward seems to be based on what he wants at the time. So, nothing too hentai. I'm guessing either a massage, possibly using bare tits, possibly pussy, or he'll be too tired and will want a good night's sleep. Possibly a lap-pillow.