When they are 'smelling the room', it is usually the second bedroom. It's not an event, and there is no solution, it's just an action. There are some of theories about it though, such as the people smelling Margaret's perfume in the doorway, since they never actually enter the room.

I'm not sure about a bathroom though, I've never seen that action.
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Solving the mysteries of Isola and Margaret and Bill.