I think I might have found a bug in the sewers when I lost one of the red keys. I have just two red keys and it makes the water pipe puzzle impossible.
Is there any way to fix this, I don't want to restart with a new game.
![](http://i.imgur.com/dlGT3.jpg)
two keys in inventry and none on wall
![](http://i.imgur.com/mu9zs.jpg)
key taken from here
![](http://i.imgur.com/7g8mK.jpg)
key taken from here