This is the forum for helping you out if you're stuck in Grimrock 2 or if you want to discuss about the mysteries of the Isle of Nex. Warning: forum contains spoilers!
still not getting this. been all over the bog. if you mean the talking heads? haven't seen more than one or two close to each other.
is there a landmark this thing is near? that would help.
or which side of the bog is it on (NSEW)?
or even, gods forbid, a picture of the map with the location marked.
ah. got it. heads, but NOT talking heads. fallen... on their sides.
(for anyone else: it's in the area where you go through a teleporter to get to one of the powerstones. you'll see 4 heads on their sides. dig in the middle of that area.)
The fallen spirits refer to the broken talking heads. In the area only accessible by teleporter there are 4 of them close by, dig in the middle of them.