Board Thread:Skyrim/@comment-110.146.134.32-20130814063646/@comment-1470368-20191121160724

Why, the Last Dragonborn of course.

You technically are a victim of this situation you've found yourself in, kidnapped as you were for "stealing" the DB's kill. Plus, the Last Dragonborn is hounded by DB assassins from the moment they step foot out of Helgen (radiant encounters in consideration).

Your only way out is to either kill one [or more] of the three potential targets of the DB, or kill Astrid herself to earn your freedom.