Someone else (Hari??) seems to have also known how to get into lazy people's mailboxes, because I found something weird in there. It was a plain envelope, no address or postage or anything. Over the seal someone had written:
X MARKS THE SPOT
Inside the envelope there were four photographs, which I've scanned for you. Here they are.




Any ideas??? Maybe we have to solve the other cipher first for this one to make sense, but we can probably start trying to figure out what these pictures mean...