You are checking in and would like a room right at the top: I’d like a room on the top floor.
The rooms up there are the most valuable ones, so you have to swear an oath not to break anything (I’d) and to like the hotel (like). In return you get an apple (a) and a small bottle of rum (room) – except that the receptionist’s uncle already lives there, currently eating a bread roll and in top shape (on the top), though with a flea in his ear (floor).