Skyrim Secondaries Intersection- Saarthal: Stop Draugring This Out

The door itself is also unlocked, and leads to a large burial hall.  Take more money from the dead via the burial urns on the altar, then move off into the hallway to discover the ramp leading down.  Hanging Moss waits for you here, as does a patch of mushrooms high up on one wall and another on the floor opposite.  The wary will note the lack of animating corpses on the ramp, and the paranoid will consider it a bad sign (remember, being right doesn't mean you're not paranoid).

A chest waits at the bottom of the ramp in a pile of rubble- just beyond a floor-plate triggered spear trap that will nail you in the side if you're incautious.  Naturally, this is immediately followed by a pair of draugr, one of them a Wight, waiting in their burial niches to ambush and kill you, just where the hall turns left.

Paranoia vindicated, you can now proceed into the next area- a series of small round burial chambers.  A large potion is hanging out in the first, and the rest are thankfully devoid of undead- just a series of the turning obelisks notorious for guarding Nordic tomb secrets.  Thankfully, though the poison dart trap surrounding the 'open' lever is particularly nasty, filling that area with flying venom from practically every angle, the puzzle is remarkably simple.  The animal that should be showing on each pillar is carved into the wall behind that pillar, up near the ceiling.  Any tomb robbers the Nords anticipated were clearly supposedly pretty daft.

After setting the pillars, apply your 'use' function to the lever to open the porticullis and enter the next hallway.  This is another short one, quickly terminating at an iron door the opens into another very large room.  This one has a raised level mostly in the center of it, attached to the far wall and attended by stairs on either side.  This room is home to one of the big bads of the undead world, a Draugr Deathlord.  This nasty corpse wields a rare and powerful weapon, and has more health than even a Scourge Lord- if you can find a way to keep it clear of you while killing it, do so.  Sneaking and ranged attacks work especially well, as do slowing effects and anything that will stagger it.  Poisons are also your friend here, provided they aren't weak enough for the Deathlord to consistently resist them.