The Knights are bedeviled by a Knightmare built on the same technology as Lancelot, but with a short-range teleport. But they fight it off in time to collapse the building on their enemies.
Zero again declares the United States of Japan, even though it's just one room.
Nunnaly is missing, of course. In her place, Lelouch has a brother, Rolo. He's obviously a spy of some sort.
He is the pilot of the experimental Knightmare. And he has a geass of his own.
Meanwhile, the Emperor shows Suzaku his secret: the Sword of Akasha: a weapon to kill God.