-The contents of the envelope which I gave to Maria was certainly the key to the chapel
This is even better.
As for Kitsu theory, it is certainly possible but do you realize how twisted is this logic? You need to imagine that Rosa sneaked inside the cousin's room just to take a peak inside Maria's letter (after midnight) and then someone else entered the room and took the key. It would make more sense if Rosa herself took the key at that time.
|