Battle of Kaminejima Island

Background
After the failed attempt in capturing the Lancelot, Zero finds himself stranded after using his Geass to order Suzaku Kururugi to "Live". Finding himself on a tropical island with, to his surprise, Euphemia Li Britannia. After a tense meeting, she declares that she knows it is Lelouch vi Britannia behind the mask of Zero. At this point Lelouch reveals that it is indeed him and Euphemia is overjoyed.

Suzaku also finds himself on the same island, however, he believes he is alone and begins scouting with a gun in hand and soon afterwards finds a nude bathing Kallen Stadtfeld. Upon noticing him, she removes a concealed knife that was inside her cell phone case and attacks Suzaku, but he manages to subdue her and throw her to the ground. The two, incredulous that they are on opposite sides, have a quick discourse before Suzkaku arrests her in the name of the Empire.

Euphemia and Zero speak as she waits for her cloths to dry wearing Zero's cloak. After a while her stomach starts to grumble and Lelouch makes an attempt to capture an animal for dinner but ultimately fails.

After that it turns to night and both Suzaku and Zero have set up camp. Suzaku urges Kallen to abandon the Black Knights, believing that she is not beyond hope and that she should not risk being caught and tried as a terrorist. In response Kallen reveals that she already fought against Suzaku in her Knightmare frame. Suzaku finally realizes that Kallen is the pilot of Guren Nishiki. Because of this, he tells her that there is no future in her ways. An angry Kallen responds by saying that Suzaku's future is that of a dog to the ruling establishment whose only purpose is to live. She then scoffs at his 'Honorary Britannian' and 'The Knight of the 3rd Princess' title, thinking that it insults the name of Genbu Kururugi.

The Battle
The following day, the Britannian Airship Avalon searches the island and finds a temple which Schneizel El Britannia orders his men to excavate this is due to the presence of a Thought Elevator, Schneizel revealing that his father has obsession with such artifacts. Rakshata Chawla also starts a search with the Black Knights to find Zero using his submarine headquarters. Sonar picks up an island which they stay in the vicinity of. Euphemia and Zero begin exploring the island for food, shelter and possibilities of rescue. Suzaku also starts a search and they both run into each other. Kallen is overjoyed to find Zero is on the island and Euphemia (who has romantic feelings for Suzaku) is also very happy to see him.

Suzaku and Zero confront each other, each unwilling to let the other escape. They are interrupted when the ground beneath them lights up, revealing a large Geass sigil. The four of them are immediately transported into the underground dig site. Seeing that they are surrounded, Zero takes the initiative to steal the Gawain to get himself and Kallen out. Thanks to its cannon and flying ability, they manage to get out safely and destroy any Knightmare frame resistance. Landing in his sub the Black Knights retreat.

Aftermath
The first important part of this battle was the discovery of Zero's true identity by Euphemia. This knowledge helps her to set up the Special Administrative Zone of Japan. She also now trusts Zero and because of that trust she eventually starts the Special Administrative Zone Massacre. Another important result of this battle is the capture of the Gawain by Zero. This super-powered unit, with its Hadron Cannon, provides air superiority in the First Assault on Tokyo Settlement as well as the much needed aid that Suzaku gets in the Battle of Fukuoka Base.