Yeah. Involves dropping off ledges but once you know the way it's easy.Is there a short cut back to Flamelurker?
From the spawn point - Go down the tunnel and turn right though another tunnel past the troll miner things (there's 2 that will kill your with a pickaxe so be careful). Smash through the boxes on the right side and drop down the ledges all the way to the bottom. Go through the tunnel and turn right to the fog door.