This quest is a continuation of " The Man who Cried Wolf ", so be sure you have done that quest before doing this one. After doing that quest, you may have to either go level up or wait 3-4 days and Falk Firebeard will send you a letter via courier .
Once you get the letter, go see him at the Blue Palace where he will tell you that despite your efforts before, Potema has been summoned and is in spirit form. We will get the quest once we agree to go talk to the Priest of Arkey, Styrr.
Once you accept the quest head to the Hall of the Dead in the city (follow the quest marker if you haven’t been there before) where you will find Styrr. Talk to him about Potema and he’ll tell you that you must go find her in her catacombs, find her remains (likely a skeleton) and bring it back to him to be blessed. He’ll give you Potema’s Catacombs Key as well.
Head back outside and head to the Temple of the Divines now (again, its in the city, just follow the marker). Head downstairs (take the left path) and open the iron gate you find with the key and proceed into Potema’s Catacombs.
Inside the catacomb, head down the stairs and stop at the dead end by the bars. Potema herself will speak to you here, saying that you will serve her when you die. After she’s done, the bars will lower. Head in and kill the Draugr in this first part and then go left to some stairs.
There is a chest under the stairs and one past the stairs. Loot both and in the next room will be two Draugr and a Vampire. Here, shoot the POT OF FIRE on the ceiling to occupty the occupants below and then take out the Draugr up above with you before cleaning up whoever survived the fire below. Also, be sure to check by the barrels below for the " Surfeit of Thieves", a LOCKPICKING SKILLBOOK.
Continue forth past a gate and kill a Draugr patrolling to the left. Notice the nearby Draugr on the wall. This one is dead, but others won’t be (there’s a fire trap in front of it too). Continue through another door where in the distance is another wall Draugr. This one is alive, so kill him. Head down the path now and to the right on the upper section a Draugr will get up.
There is another one further down too (and potions on the left-hand wall) so kill them all and continue. You’ll go down some stairs and kill a vampire in the hallway beyond before coming to a room with some water on the left. Be ready here, as the Draugr will rise out of the water! Kill them and watch out for trap pressure plates on the floor as you leave.
After that room you’ll head down some stairs and Draugr will be waiting for you on the right (two of them). Take them out and go examine the treasure chest on the left. It is trapped, so undo the trap or open it from the side.
Head down the tunnel now and hit the lever, which will start a spinning wall door where an iron gate will appear as the stone spins around and it will open randomly, so whenever the gate appears AND is open, RUN through the trap! Beyond that is a bunch of potions on the ground near an alchemy lab, so take them and use the lab if you wish before heading into Potema’s Refuge.
Head down the tunnel and at the opening kill the Draugr to the left (a deathlord for me, he was staring off to the left letting me do a sneak attack with ease!). Head right now and soon you’ll hear and see another rotating stone door. Before going through it, open the door to the right and kill the vampire inside. Now, look behind the coffin and pull the lever.
It opens a stone door to the right that leads to a treasure chest! Sweet! Head back now to the rotating stone door. There are actually THREE stone doors here, but there are three levers as well. What you need to do is use the levers to STOP the rotating. The levers can make the doors go left or right or, when in the middle, can STOP the door.
Make it so that each door is stopped with the gate open (which isn’t hard to do, but does require patience). After the doors will be two soul gems that will shoot fireballs at you, so heal yourself and run up to them and take them to make them stop. Past that is a big room with another vampire and a Draugr for you to kill. Take them out and head down the stairs into Potema’s Sanctum.
In here head forward through the door to a burial preparation room. In the door beyond you will find 2-3 Draugr AND a Vampire, so be ready for those kind of numbers (I fought 3 Draugr, a Skeleton, and a Vampire - something area-of-effect related would be useful here). Beyond that is a room FULL of dead Draugr.
It’s a dead end, but go in and start looting the dead (take their WEAPONS too, even if just for right now) and soon Potema will speak to you again. She will then revive three of the bodies here and they will attack you (if you took their weapons, they will be weapon-less). Take them out and drop whatever items you don’t want (or continue looting) and continue to an iron door. This is a good place to save by the way.
Head inside the door where the spirit of Potema will be swirling around above you. It will ask you once again to die and join her army, but then it will start reviving nearby Draugr and sending them at you! It will also send a wave of electricity randomly around the room that WILL hurt you if you touch it (it goes around in a circle).
Sneaky types can easily hide out by the door even when the waves of Draugr spawn, although there are a few spawning points by the door as well. Each wave will have 3-4 Draugr in it and you’ll be facing three waves. Take them out like you would any other enemy, but think of using a shout or summoned companions to help you out.
At the end, you will be told to find Potema’s remains and the spirit will fly through the far door, opening it up! However, Potema’s spirit will now attack in ghostly form! Take it out (it isn’t too hard) but be aware that it will try to raise the dead Draugr to help it.
After killing the spirit, loot it for an enchanted weapon and head through the door it opened to find Potema’s Skull on the throne. Grab it and then loot the chest nearby for several impressive items, including the RALLY spell and "The Legend of Kratley House", a SNEAKING SKILLBOOK .
Head up through the door now and into another room. There’s a pedestal with a dwarven helmet on it, but don’t focus on that and focus on killing the two Draugr to the left and right of the pedestal. Loot them and open the door leading to Skyrim in front of you.
You will be in the mountains above Solitude now. Loot the chest nearby for some goodies and fast-travel back to Solitude. Our first stop should be to the Hall of the Dead to give the remains to Styrr. Give him the skull and he will be thankful. Now, head over to the Blue Palace and go report back to Falk who will thank you as well, but with money! He will pay you 1800 Septims and give you the "Shield of Solitude" as a reward:
- SHIELD OF SOLITUDE: Increases Magic Resistance by 30%. Block 35% more damage with your shield. You will now be done with this quest. Congrats, protector of Solitude!