Achashverosh's Shock and Fury/1

Achashverosh's Surprise

Introduction

Why So Shocked?

Esther Chapter Seven contains one of the most dramatic scenes of the Megillah. Esther pleas for her life and that of her nation, finally revealing her identity and exposing Haman's plot to the king.  Achashverosh responds with shock, asking "מִי הוּא זֶה וְאֵי זֶה הוּא", who  is the one who conceived of such a plan? Upon hearing that Haman is the mastermind, he leaves the room in a fury.

How is one to understand the king's surprised reaction? How could he not know of Haman's involvement?  After all, it was just a few days earlier that he gave his approval for the plan!  Even if the king had been unaware until this moment that Esther was to be a victim, he still should have known that Haman was the plan's architect?  Moreover, considering that he himself had played a role, why is Achashverosh so angry at Haman?