It's wrong to drug people.
Will met a girl he likes at a bar, and he wants to take her home with him.
Will wants to have sex with the girl.
Will has a conversation with the girl and asks her to come to his place.
Will puts something in the girl's drink that slows down her thinking.
The girl is more willing to go with him and have sex.
The girl finds out that Will drugged her and thinks about getting legal action.