- Speak with Mirabelle. Ask her the appropriate questions to advance the quest line.
- Travel to the ruins of Mzulft.
- Enter the main door to Mzulft and listen to the dying Synod researcher explain how the Falmer attacked and took an object called the Focusing Crystal.
- Follow the quest arrow to Aedrome and kill any enemies necessary to reach your goal.
- Once you reach the Aedrome, you must fight a leveled boss which will have the Focusing Crystal, be sure to take this from him. Next, you will go further into the dungeon and find a room with a leveled monster, in this room are beds as well as a dwemer chest that contains the key to Oculory.
- Return to the main chamber of the aedrome and unlock the door that requires the key you just retrived. Paratus Decimius will let you into the Oculory.
- Speak to Paratus and place the Crystal in the Oculory. Cast three ice spells (Frostbite works best for aiming) at the assembly you just placed and then align the large green circles on the ceiling the the beams of light to focus the Oculory. Then speak to Paratus again and listen to him whine about the College.
- Leave Mzulft (through the Observatory door if you killed the Dwarven Centurion in the room just off where you looted the Focusing Crystal) and return to Savos Aren. He and Mirabelle will be attempting to bypass a ward – speak to Savos Aren, who will request your assitance in doing so, and cast spells at the ward. I suggest one of the first three elemental spells since they are continuous cast and won’t hurt your friends.
- Watch the scene, then exit to the courtyard where you will find Savos. Do as you are told and dutifully protect Winterhold.
The arch mage has mentioned that Mirabelle was talking about the Staff of Magnus not too long ago. Ask her what she knows about it and its whereabouts.
She will direct you to the Mzulft, as a group calling itself the Synod have approached her and asked her about it in a secretive manner. The Synod are a group of mages who hail from Cyrodiil, and are pretty much the remnant of the Mages Guild there. When you arrive at Mzulft, you will immediately encounter one of the members of the order near the door, who refers to the Falmer and then dies. Loot him. Now you will have to go through the long path that takes you to your eventual destination. You will be attacked by the standard ancient cave creatures, and Mzulft is full of good loot, lots of Dwemer items (including at least 10 Cogs for a Miscellaneous Quest).