Elena asked to check in four hours earlier than normal check in time. We told her we would accommodate her request, and have the room ready by 11am. We asked her and her boyfriend later in the day, if their needs were met and if the accommodations were acceptable. We were told all was well. They seemed content. Upon the following day, we learned through Air B&B that they had checked out early, citing a non existent mold issue. It seems they had mistaken the painted faux granite finish on our landing, for mold. To date, no one else has ever mentioned this. If our guests had only voiced their concern, instead of slipping out without a word, I would have eased their concern, by pointing out what should have been obvious - that what they perceived to be mold, was in fact a painted surface, speckled to resemble granite. This is known as a "faux finish", and is meant to beautify what would otherwise be a non-descript stairway landing. There was zero communication from our guests, and their concern could easily have been laid to rest, had they mentioned it. Their concern was unfounded.