After leaving the thaig they're pursued for a time, darkspawn coming out of the stonework in force to make sure they really do leave the Old God alone in its prison. But the darkspawn taper off along with the echoes of the song. Back to normal, band-every-hour-or-two levels.
The way back takes longer than the journey down. The Wardens who came before scratched symbols into the walls to mark the way, noted statues and landmarks, and left behind signs of exploration. It all needs to be scrubbed: the symbols obscured or re-scratched in the wrong tunnels, the statues torn down or moved. The weaker bridges can be collapsed. So can the tunnels themselves, sometimes, where they're already looking unsound. Signs of an ancient camp where the Deep Roads branch in one direction are carefully moved to another. Traps and wards, both magic and not, are set along the way.
Someone needs to take notes: follow this symbol, not that one. Disarm that trap first. Find a way across the chasm without a bridge, sorry. The nontainted of the group are charged with more than their fair share, sent to branching paths to decide how to mark them and keeping their own set of notes, half of the information on the way forward kept segregated--constructing a long puzzle that the Wardens, not even the ones here, can't easily solve on their own.
Their original entrance into the Deep Roads, a hole torn in the dwarven walls and the long dark mining tunnel, is collapsible, too. On the other side of it, there's sunlight.
OOC | More make your own adventure time! Top-level and kill more darkspawn/spiders/deepstalkers, get trapped in minor cave-ins or almost fall off a crumbling ledge, set traps and wards/seals, complain more. If you aren't sure if you're allowed to do something, the answer is 99% likely to be yes, so just do it.
( the gang wrecks some shit )