You were within that particular Jail Cell of the Imperial Prison for a reason.
Embark upon a more Dark Quest: the quest behind the premise.

(Do you remember the Wooden Mask, & how it caused the player to travel back in time? Who likes murderous invading Barbarians anyway? & why would you explain?! It's not like the Nords asked the Dunmer for permission to nearly genocide their people & steal so much of their land!)

So, embark upon a journey of a higher purpose & intelligence: Daedric Champion Series.

(Yeah. I want to make some original questline for Oblivion. :-D)