The remarkable journey of Isaiah's I iPad

We lost it in Vienna and managed to retrace our tracks to conclude we had left it at the Globe Museum. The museum was closed when we went back and because we were leaving early the next day, Isaiah stuffed a yellow post-it note with our email areas on under the door. 
He gently blew it to make sure it went through to the other side. 
Remarkably, the post-it was picked up by a securiry guard the next morning initiating a chain of events that culminated in it arriving on the post today.