Where's the key to the cells on level 2?
Solution 1:
I actually had a huge problem with this.
But, I finally figured it out! If you backtrack to the hallway, you'll see a cell with some arrows, and a pile of cloth on the ground. You can actually click on the cloth through the cell door to pick it up.
Underneath this pile of cloth (a vest), you will find the key!
Map location
Picture of the cell originally
Key!