Code Geass: Lelouch of the Rebellion: Season 2, Episode 10

2 - 10: Turn 10 - When Shen Hu Wins Glory

Zero absconds with the empress, taking her out of the Vermilion City. Before he can get far, they are stopped by an unknown Knightmare. The Chinese Federation gains the advantage, taking one of the Black Knights hostage. Can the Knights afford the loss?