I went out the back door, across the marble terrace and down into the garden, as I had done so many times before. I looked up at the two windows I had calculated as belonging to the locked room. There was nothing to see. As always, they were covered with blackout paper. Nothing had changed. Walking back and forth, I studied all of the protrusions on the back wall: window frames, downpipes. I couldn’t see any way of climbing up without a ladder. It wasn’t even possible to reach them from the window of another room.