Obtain the Neferset Key from Kavem the Callous.
Kavem was cruel enough before the Neferset signed up with Deathwing. His pleasure in deriving pain now borders on the insane.
It is he who now holds the keys to our shackles.
He dwells in the building next to us, to my right.
Find him and take the key from him. Do not hesitate or show him mercy. He will slit your throat and think nothing of it.