There much easier ways to do things."It's crazy I know, but I have seen at least one." Aoi finds a lake that has a clear sparkling look to it. She freezes the water so that she can walk across it and look to see if she can find a key underneath.
Waves right hand over ground. The earth below rattles and shakes. A stone slab breaks through the ice. On top of the stone lays a small silver lock box.
Perhaps the key is in there?