A way to get into mzulft if unable to talk to gavros plinius to get the key for the door is use the console and type in the following player additem 0005dcb9 1 to get the key.
Key to locked door in mzulft aedrome.
Mzulft aedrome in a chest in the easternmost room.
Mzulft is an ancient dwemer ruin in the elder scrolls v.
Carried by gavros plinius who does not appear until the college of winterhold quest revealing the unseen.
Go all the way to the end of that path and there will be a boss that depends on your level.
Try to unlock the door and you ll hear the voice of paratus decimius from behind it.
Having trouble finding the key.
Go through the right door go all the way down to the bottom kill the mini boss then get the key from the chest 0 13 0.
The first locked door s key is through the door on the opposite side of the room.
Or you could hit the tilde key in front of the locked door click on the door and type unlock if the door was targeted in the console it will say unlocked door of course thats just for the pc.
It is quite a distance southeast of windhelm and a short distance directly north of cragslane cavern.
It is found along the western side of the mountains of eastmarch.
Pc 360 ps3 sometimes ending the quest will not trigger the next quest in the series.
This ruin cannot be explored unless the dragonborn has been sent here by mirabelle ervine to retrieve the staff of magnus as part of the quest revealing the unseen because the key required to unlock the inner door after entering mzulft is found on the body.
Opens a door just inside the main entrance to mzulft granting access to the vast majority of the place.
Below tags are for google search to combine if someones using a lot of words skyrim locked door skyrim t.