Arc Light of the Point at Infinity

Steins;Gate – Arc Light of the Point of Infinity (STEINS;GATE 『無限遠点のアークライト』 Mugen Enten no Arc Light?) Is a drama CD from 2010 and was adapted in manga form in 2014. They tell the story of what Mayuri experiences during the final chapter of the visual novel and the lives of Mayuri, Okabe, Daru, Suzuha, and Ruka in the year after Okabe's first failed attempt to save Kurisu in the 1.129848% β world line divergence.

Drama CD
Steins;Gate Drama CD β Arc Light of the Point of Infinity Divergence １．１３０２０５％(STEINS;GATEドラマCD β『無限遠点のアークライト』ダイバージェンス１．１３０２０５％ - Mugenenten no Arclight) was first released on April 28, 2010.

Preview
A mysterious call from a time traveller will lead Mayuri to have the determination to make Okabe try again after his first, scarring failed attempt to save Kurisu from being murdered.

Chapters:

 * 01. 1.130205%
 * 02. 1.129848%
 * 03. 1.129848%
 * 04. 1.129848%
 * 05. 1.129848%
 * 06. 1.129848%
 * 07. 1.130205%
 * 08. 1.130212%
 * 09. 1.130205%

Main

 * Shiina Mayuri
 * Hashida Itaru
 * Amane Suzuha
 * Okabe Rintarou

Supporting

 * Urushibara Ruka

Plot

 * 01. 1.130205%
 * When Okabe time travels with Suzuha to the 28th of July for the first time, he has Mayuri hold on to his cellphone for him. Just as the time machine is disappearing, a second one appears beside it, stunning Mayuri and Daru. Even stranger, Okabe's phone begins to ring with a call from Mayuri's phone even though she isn't using hers.  When Mayuri answers the phone, a female voice begs Mayuri to stay calm and listen to her story.
 * 02. 1.129848%
 * The voice tells how "Okarin" traveled back in time with Amane Suzuha on August 21st to July 28th to save a person named "Makise Kurisu". Someone who it seemed Okarin was in love with. However, upon Okarin's return, he was covered in blood, shaken and severely suffering to the point of breaking. Seeing Okarin in pain like this and hearing that the time travel had caused Okarin to become Makise Kurisu's murderer, Mayuri protects Okarin from Suzuha trying to force Okarin to try again. Even upon being told abstractly of Okarin's power to observe worlds, she defends him, unable to accept putting the fate of the world all solely on Okarin's shoulders when he is like this.
 * Suzuha takes a step back, but declares that she will not return to the future. She will remain here to try again. However, due to a lack of fuel, even when making a one-way trip, in less than a year from now they would no longer be able to reach July 28th, 2010.
 * Mayuri continues to call Okarin's name, trying to pull him back from his grief just like he did for her when her grandmother died.
 * 03. 1.129848%
 * After that, things grew darker for Mayuri. The following year, July 7th, 2011, it is a rainy day on Tanabata. Mayuri and Ruka meet while leaving school. They discuss Mayuri's love for Tanabata and the legend of Hikoboshi(Altair) and Orihime(Vega/Arc-light of the Sky). Mayuri reveals that every year her impossible wish for Tanabata was "to become Orihime."
 * Ruka hopes that Mayuri will become Okabe's "Orihime". Mayuri denies, but Ruka says that he has noticed that something happened to Okabe and that it is thanks to Mayuri this past year that Okabe has been able to stand again, which is why he believes she can become Okabe's "Orihime". Mayuri corrects Ruka again. The one in Okabe's heart is not Mayuri but a person like the stars in the sky who can never be reached, because that person cannot shine anymore.
 * 04. 1.129848%
 * While it is still raining, Mayuri waits for Okabe at the Tokyo Electronics University. The narrating voice tells that in the past year it has become very hard for her to visit the lab anymore, so she would meet up with Okarin after his university classes, instead. From the two's conversation it is clear that Okabe has buried his personality as Hououin Kyouma, become active in university life, hardly goes to the lab, and is pushing himself to forget and let go. When Mayuri asks him if he is pushing himself, he replies that "playtime" is over.
 * However, Mayuri tells him that she feels somehow like the lab used to be much more lively with many people and now has become lonely. She asks him if this is related to Makise Kurisu, but he is vehement as he painfully replies that they cannot be related. He flees by deciding to go to a drinking party he was just invited to. Mayuri seeing straight through his lies is saddened.
 * 05. 1.129848%
 * At the lab, Daru arrives with one of Suzuha's favorite cakes as a farewell gift. Suzuha reflects that she wasn't able to convince Okabe after all, and wonders if she should threaten him at gunpoint like she did half a year ago. Daru discourages her from this, reminding her of the police getting involved then. Suzuha replies that she didn't think that a single gun would be such a big deal in this time period.
 * It turns out Daru even bought enough cake for Mayuri and Okabe in the hopes that they will come to the lab.
 * When Mayuri appears just then, she apologizes to Suzuha for not being able to convince Okabe to time travel with Suzuha, because Mayuri did not want to convince him to do so. However, Suzuha tells her not to mind it and that she was planning to travel alone. This brings Mayuri to ask Suzuha about the Mayuri and Okabe of 2036. Suzuha questions why Mayuri wishes to know about this only now. Mayuri tells her that she had not asked sooner because she was afraid of knowing the future.
 * Even upon hearing that the future is cruel to Mayuri, Mayuri still chooses to know, so Suzuha tells her that the Mayuri she knew was always staring lonely at the sky. When Mayuri asks if Okabe really died in 2025, Suzuha tells her that he died protecting Mayuri from gunshot in a burglary during the war. This horrifies Mayuri, as Suzuha continues to reflect that though Okabe holds the fate of billions of people on his shoulders now, he is easily killed in fourteen years. She says that Mayuri seemed to feel painfully responsible for that. Mayuri used to say, "On that day, if my 'Hikoboshi-sama' had risen again, everything might have changed."
 * With that, it is time for Suzuha to go. Mayuri asks her if she really will go. What will happen to Suzuha if she fails? Will she relive this past year? However, Suzuha doesn't know. Herself of this past year and herself that will travel now and be stuck in the past will be different people. She predicts that eventually world line convergence would correct a "distortion" like her. Mayuri panics to stop her and turns to Daru, but he simply encourages Suzuha. With an "Okey Dokey," Suzuha departs the lab.
 * 06. 1.129848%
 * 07. 1.130205%
 * 08. 1.130212%
 * 09. 1.130205%
 * 09. 1.130205%

Manga
Steins;Gate – Arc Light of the Point of Infinity (STEINS;GATE 無限遠点のアークライト) The manga adaptation was illustrated by Nariie Shinichirou, who was also the artist behind the manga adaptation of Babel of the Grieved Maze. It was serialized in Shueisha's Ultra Jump magazine between April 19th and August 19th, 2014. On November 19th of the same year, it was published as a single volume ISBN 978-4088900322. The manga adaptation includes small additions, such as starting with a short prologue depicting the Mayuri of 2036, divergence 1.129848% in the war zone city of Akihabara, speaking her own words of regret. The story also ends with a three page epilogue.