The hall turns right after the cookfire, resuming its original direction, becoming less steamwork and more ruined, half-collapsed stonework. Another Dwarven Sphere Guardian ‘corpse’ marks the end of the hallway, which is patrolled by yet another bandit archer. Slay the archer and loot her and the defunct result of ancient artifice and you can take a left down into a more cavern-like area rimed with snow.
This alteration in the dungeon environment is very brief- it encompasses a few meters of hall and a single ‘room’ to the right, where a pair of bandit mages make their home. Neither of them is prepared for a physical assault of any sort, so as long as you use weapons you won’t have to worry about their defenses and can wipe them out pretty quickly. In addition to whatever they were carrying on them, the two mages also have several barrels of food, some gear lying around, a pair of valuable Magicka potions on the table with a set of fur armor, and an unlocked chest that likely only contains money and perhaps a lockpick or two.
Once you’ve overcome this bandit guard post, continue into the stone hall ahead, where four things of note wait for you. First, a Dwarven Sphere Guardian lies ruined on the floor in plain sight. Second, a bandit in heavy armor is guarding the area before the third item of importance, a large locked Dwemer metal door. Finally, opposite the large door is a ramp heading further down into the Mzinchaleft complex.
The bandit holds the key to the door, though you can easily just pick the lock, and the room is known as ‘Maluril’s Room’, if the key is anything to go by. The room holds several stone beds, and a table on which lies the remains of a Dwarven Spider. Pick through the machine’s inert body and you can also scrounge up a pair of valuable potions and Maluril’s Journal. The journal is an interesting read- from it you can tell that Maluril is some sort of ne’er do well who only escaped capture by guards in Cyrodiil via sweet-talking his way out of the city. He came to Skyrim in search of Dwarven ruins, his caravan ambushed by bandits who another member of the caravan talked into working for Maluril to excavate Dwemer artifacts.
In addition to this, a Speechcraft book sits on one of the tables between the beds, so make sure to have a look at that as well.