If the property was indeed purchased at a foreclosure sale, the sale would have extinguished any junior liens. Unless your state does things in a weird way, the second lost its lien position and cannot proceed with a foreclosure.
In as much as the underlying debt was discharged any attempt to collect from you is a violation of the discharge injunction of 11 USC 524. Send a nasty, nasty letter and if you were served with a law suit, file an Answer and Counter-claim for damages resulting from the emotional distress you are now feeling. Make sure your Answer also asserts the Affirmative Defense of "discharge in bankruptcy".

