The common theory is that the doctor will be Aiden's mom. That is the connection.Of course, it's an outrageous assumption, and everyone's guessing that the last character is the doctor, but I'd like it to be a bit of a surprise, because the doctor doesn't seem to have a strong connection to the character that's out there right now, the teacher and her daughter, the sister and her best friend, and, you know, if there's at least one independent character whose content can't easily relate to our daily lives, After all, who goes to the hospital every day.