Just a warning in the Foundry when looking for the second Heartstone, in the room where its located a construct is need to complete the puzzle rooms. However its possible toto get it permanantly stuck on geometry in my case the rubble to the right of the key door. As far as i know this is a game breaker with no way to reset it. Its just happened to me and i'm pretty fucked off in truth,i have very little time to play games these days and i won't be starting the game again any time soon. Take care in that room.