The Distant Valhalla

The Distant Valhalla is a Steins;Gate light novel set in the Alpha Attractor Field. It takes place on worldline divergence 0.334581%, a year and a half after the Rounders raided the Future Gadget Lab and captured Rintaro Okabe, Kurisu Makise, and Itaru Hashida. The story was written by Naotaka Hayashi (the Steins;Gate visual novel's main writer), and features art by Juu Ayakura. It was originally released on August 13, 2010.

Synopsis
The story is told from Okabe's perspective, a year and a half after the Rounders raided the Future Gadget Lab, captured Okabe, Daru, and Kurisu, and killed Mayuri Shiina. The captured trio lived out the year and a half after the attack at the SERN facility near the France and Switzerland border, their actions carefully monitored.

Though Daru and Okabe were allowed to stay together, Kurisu was separated from them and held in a different building; as a result, Okabe and Kurisu had not seen each other since the attack on the lab. The novel opens with Okabe and Kurisu's first reunion since the attack, where Okabe outlines "Operation Valhalla", his plan to escape from SERN and return to Akihabara alongside Kurisu and Daru.

Trivia

 * Although its original format is a light novel, The Distant Valhalla has been remade into a visual novel by fans.
 * The Distant Valhalla was partially adapted into an anime-like format through Steins;Gate-themed pachinko machines in Japan.