Halldir's Cairn

Summary
It is a cave found southwest of Falkreath. Several quests are focused here which may be spoiled by premature exploration. This is a small-to-moderate sized single-level dungeon with undead foes and moderately difficult bosses.

Quests

 * Find Runil's Journal
 * Find Rjorn's Drum - Inside the chest in the final room, where Halldir is found
 * Ancient Power - Inside the chest in the final room, where Halldir is found
 * Trouble in Skyrim - Kill the leader of Halldir's Cairn
 * Amulets of Night Power (Dawnguard) - Possible location of one of Amulets of Night Power

Walkthrough
Just inside the entrance of the cave, there will be a column of blue light and three dead bodies around it - They are Agrius, Raen and Vidgrod.

On a pedestal near the column is a journal, telling of a ghostly voice compelling the bandits to kill themselves on a blood-soaked rock cairn, as well as a key to the only door going further inside the cave, (Key to Halldir’s Crypt). This first room has no enemies and has numerous mushrooms.

Eventually, the Dragonborn will reach a Draugr sitting on a throne. After a fight, there will be an iron gate which is opened with a lever that is located behind the throne. Hostile Ghosts appear as the player advances through the catacombs.

A room with a Pillar Puzzle is the next challenge. Rotate the three pillars in the room, so that the symbols on the pillars match the symbols on the walls opposite them, (Bird, Snake, Fish), then pull a lever to advance to the next room. Incorrect combinations result in a dart trap shooting poisoned darts when the lever is pulled.

Once the first step is taken into the final room, a fight against Halldir will begin. He uses strong Destruction spells. When reduced to about two-thirds of his health he will use a special ability to produce three copies of himself. These use ice, fire and lightning spells individually. Once all three forms have been defeated, Halldir appears back in the middle of the room to finish the fight. ''NOTE: If you are able to do sufficient damage with a single bow shot, you can kill him immediately and the three 'incarnations' do not appear. (Ebony Bow-Exquisite, Dwarven Arrow, dbl damage perk, 3x sneak attack plus stacked (40%) archery damage mods)''

Halldir drops a random Ancient Nord Sword or an Ancient Nord War Axe with a random enchantment, some gold and Halldir's Staff, which has a Calm and Soul Trap effect. After Halldir is killed, a trap door in the center of the room can be opened to return to the initial room of the cavern. The blood covered Cairn will now be gone. All that is left are some rocks on the floor where the cairn was.

It is a long drop down. To avoid injury, drop to the first partial platform, and then the second before dropping to the floor.

Notable Loot

 * Two of Halldir's Staves One from his Ash Pile and one that drops from his hand when killed.)
 * Rjorn's Drum
 * Agrius's Journal
 * Soul Gems
 * Black Soul Gem

Alchemy Ingredients
Mostly mushrooms, mostly in the first room. Approximate numbers:
 * 7x Bleeding Crown
 * 7x Blisterwort
 * 11x Fly Amanita
 * 20x Imp Stool
 * 19x Namira's Rot
 * 19x White Cap

Bugs

 * Sometimes the Pillar Puzzle will not turn properly when activated, to fix this reload the cave.
 * As this dungeon can be entered several times for different quests, sometimes the object of the venture cannot be obtained, and the quest cannot be finished. For example, if Rjorn's Drum is picked up the first time in the Cairn without having activated that quest, the quest to find it can not be completed. Or, if entered after the first time to kill the leader, (Companion's repeatable quest), killing the Dragon Priest that spawns instead of Halldir does NOT complete the quest.
 * Halldir may spawn completely invisible for no apparent reason along with his copies.
 * Sometimes if you pick up Halldir's staff from his dead remains, it's possible to obtain another staff on the ground. Resulting in two staffs.