ugh, this is dangerously close to one of my feature ideas involving memory-replacement surgery.

logline: An amnesiac nun, wrongly sentenced to Hell, returns to Earth to find her murderer and prove that the person they have on file, a ruthless assassin, isn't her

This sounds a bit like LA FEMME NIKITA:

A thief/junkie is recruitd by the government & trained to be an assassin.

@Eve Montana and Laura Reyna: Don't forget Hwood's mantra: "similar but different." It all boils down to how similar something is and how different it is. Ironically the similar part is a plus in that a script which is similar (but different) to a successful movie can elevate a buyer's comfort level in spending $$ on the script.