The Black Knights' reorganization into a cell-based command structure proceeds smoothly, while the Black Knights also expect aid to come from an Indian scientist for the Guren, Rakshata Chawla. At the same time, C.C. is arranging to meet with an ambassador with the Chinese Federation.
Unbeknownst to everyone, Mao survived his last run-in with Lelouch, albeit heavily injured and now covered in bandages: Lelouch had told the cops just to shoot him, not to kill him.
While Milly is sent on a date with Lloyd, an Earl in the Britannian court, and the Earl suggests getting married immediately, Lelouch returns home to find, to his horror, that Nunnally has been kidnapped! Mao calls Lelouch, warning him that he has five hours to find him and Nunnally, and that he cannot use the cops again. Since Lelouch is within range of Mao's Geass, Lelouch searches the school grounds. Suzaku finds out about Nunnally, and agrees to help Lelouch find his sister.
Lelouch recalls hearing running water when Mao called him, leaving one place: the school's water circulation systems. When they find Nunnally, they find a pendulum bomb strapped overhead: any disruption to the bomb's movement would cause it to detonate, and Mao has a camera trained on her and a remote trigger in case they try to move her. Suzaku pledges to disarm the bomb while Lelouch deals with Mao.
Lelouch confronts Mao in the schools clock tower, where Mao challenges him to another game of chess, this time with a scale for placing captured pieces that would detonate the bomb if Mao wins, or disarm it if Lelouch wins. Unfortunately, Mao's Geass gives him an unbeatable advantage. In desperation, Lelouch surrenders to Mao and begs him to release Nunnally, only for Mao to toss one final chess piece onto the scale, winning the game.
When Mao checks the security camera, however, Nunnally is still alive! Suzaku had disarmed the bomb, just as Lelouch had planned: Lelouch used his Geass on himself, using a mirror, to compel himself to forget about his plan with Suzaku before confronting Mao, so Mao would not be able to learn of his plan to defeat him.
When Suzaku appears and disarms Mao before going to apprehend him, however, Mao suddenly calls Suzaku a "father killer". Mao had peered into Suzaku's mind and discovered the truth about Prime Minister Genbu Kururugi; he did not commit suicide to protest Japan's war with Britannia, but advocated continued resistance against the invaders, even though such action was futile. Suzaku stabbed his father out of desperation, and the death was covered up as a suicide. Suzaku's overwhelming guilt for killing his father was what drove him to put himself in danger as a soldier: it wasn't just to be a hero, but also to find absolution for the sin he had committed.
As Suzaku breaks down under Mao's taunting, Lelouch, in a rage, uses his Geass upon Mao with the command: "NEVER SPEAK AGAIN!" As Mao is rendered completely mute. He runs outside and is greeted by C.C., who ends his suffering with a bullet to his neck.
Thus, Lelouch is left alone with an emotionally devastated Suzaku...
