Entering the inn, you can bring the journal to Wilhelm.  He explains the haunting of the barrow- until you give him the journal.  Astounded by how easily everyone was fooled, he gives you something special in return- the Sapphire Claw.  This dragon’s-foot shaped tool will allow you to open the door.  What door?  Well, the one down the other direction of the intersection back in the Barrow.

By heading back into the Barrow and taking the other turn by Wyndelius’ study, you find yourself in a room that’s pretty familiar- except that the bears have been replaced with wolves.  While you’re tweaking the door, be careful- trying it with the wrong combination of animals will get you shot full of arrows or crisped, if you’re foolish enough to stand right up next to the door.  Fortunately, these can be avoided by standing back at your full reach while you poke the lock.

As per the animal carvings on the walls, the order is Bug, Bird, Wolf- so set the three rings, insert the claw, and in you go.  There’s a short hall with not much in it other than an aggravating trap triggered by trip wire- though you can turn them it with a wall chain immediately the other side of the doorway.

Keep your eyes peeled for more pressure plates- the doorway leading on is trapped.  When you get near it, it closes and a side portcullis opens.  This exposes the lever to open the door, but it also triggers the awakening of some draugr.  The draugr in here are rather tough, some of them wielding sword or axe alongside a frost spell, their blade envenomed with frost weakness poison.  Shield bashing will stop the constant stream of chill, though, and that makes things a lot easier- or you could just hit them hard and fast, either one works.

After this you encounter another spiral stairway- stepping into the stairwell triggers the gate to drop, dumping you into the water if you’re not cautious.  Fortunately, this is more reward than trap- there’s a quality sword and some money under the water, and you can just reach up and pull the chain to make the gate rise again, lifting you out of the water if you hadn’t already climbed out yourself.

At the top of this stairwell, where you should go before heading through the mid-level door, is a Master-locked door, behind which is an Expert locked chest- this will net you quite a lot of lockpicking experience as long as you’re careful enough to be able to unlock the door.