Head to Darktown and find Anders in his clinic; agree to aid him in his quest. Head out of the clinic and snag the deathroot by the steps then make your way south to the Gallows Dungeon. Search the bones and take the top path first to find a pile of bones , crate , and spindleweed . Backtrack and head south past the corpse to find a hostile group. Defeat them and be sure to loot the Fine Dwarven Trousers off the bodies, then take the eastern path to a corpse then further south to a pile of bones and a deep mushroom .
You can spot a corpse further south but going west will have you pass a trap - complex . Disarming or tripping it causes spiders to attack from all sides. Head back north up the western half and button hook into an alcove for a chest - complex . Head back south where you’ll spot two sets of bones , but continue to follow the path until you meet more Lyrium Smugglers. Head up the steps and check the little cubbies for a chest . At the top of the stairs are two corpses and a greeting of hostility.
Continue going up the steps while looting the corpse and two bone piles. As you reach the end of the path Anders goes postal and you are thrust into combat. After the battle Anders is still under the control of Justice, talk him down to gain high Friendship or do the opposite for high Rivalry. Loot the bodies for Alrik’s Papers and Dissension then check the western crevices for a crate containing Spirit Essence and a chest - complex . A corpse and The Enigma of Kirkwall can be found on the other side, grab them and find Anders back at the clinic.