"Though WWIII is on the horizon, Okabe attempts to live a normal college life. However, a newly developed AI is about to shake up his world."

"After a chance encounter with Maho where they discover knowing someone in common, Okabe has his first face-to-face with her special AI, Amadeus."

"Mayuri tries to bring everyone together for a Christmas party at the lab, but Okabe has a rude awakening."

"While Okabe Rintarou briefly has a vision of a world line where he is caught up in the middle of a war, which he eventually comes to realize was his Reading Steiner taking effect. Meanwhile, Suzuha explains to Daru that she is looking for Kagari Shiina, Mayuri's future adopted daughter who time-traveled with her from the year 2036 but became separated from her in 1998. As Rintarou decides to help with the search, he gets a call from Ruka Urashibara about a pressing matter before finding Moeka before his doorstep. be is left with more questions than answers, Suzuha recruits help in her search for an unexpectedly close person."

"Their search continues as New Years swiftly approaches, though Ruka's dilemma with a certain guest might make matters worse."

"Now that the girl's identity is known, Okabe and friends kick off the New Years with a shrine visit and party to never forget."

"The armed men attempt to abduct Kagari but are forced to flee empty-handed when Yugo Tennouji arrives and disarms them. Concluding that group are not the same Rounders he had previously encountered, Rintaro approaches Tennouji, using his knowledge over him being a member of a Rounders to acquire his help in protecting Kagari. Meanwhile, as Maho continues to find herself locked out of Amadeus, Ruka tries to question of Suzuha over what everyone is keeping from him. Later, Rintaro suddenly receives a distress call from Amadeus, at which point his Reading Steiner activates and he is sent to another world line where Kurisu is still alive."

"Rintaro soon comes to realise that he has once again ended up in the alpha world line where Mayuri is dead, as the Rintaro of this world line couldn't go through with sacrificing Kurisu in order to save her. Realising that this Rintaro came from another world line, Kurisu reveals she has rebuilt the Phone Microwave, asking him to use it to return to his world line. As Rintaro struggles with his decision, Kurisu takes him to Mayuri's grave, urging him to wake up from his dream. After advising Rintaro not to interact so much with Amadeus, Kurisu kisses Rintaro before sending a D-Mail, returning him to the beta world line."

"As Rintaro arrives back in the beta world line, where Amadeus' takeover has been prevented, he discovers Mayuri's friend Katsumi \"Fubuki\" Nakase, who was hospitalized after they both collapsed, has memories of the alpha world line he was just in. After arranging for Maho to stay with Faris after her hotel is burgled, Rintaro is questioned by Suzuha about the shift in world line, revealing that it was caused by time machine experiments by America and Russia. Fearing she is running out of time, Suzuha tries to force Rintaro to go back in time with her, but Daru convinces her to stop. Later, Tennouji informs Rintaro about an organisation known as DURPA, leading him to suspect that they may be targeting Amadeus in order to obtain Kurisu's time machine theory. Rintaro asks Maho if she possesses any of Kurisu's research, but she lies and keeps secret from him the fact she has Kurisu's personal laptop."

"Hiring Moeka as a bodyguard, Maho gets Amadeus running again and resumes testing with Rintaro before having a slumber party with Faris and Moeka. The next day, Rintaro, Maho, and Amadeus spend the day going around Akihabara, ending up at the Radio Building where Kurisu was killed. After Maho reveals to him that she possesses Kurisu's laptop, Rintaro warns her that the data on it is what will spark World War III."

"Meeting up with Daru, who had been hired by Maho to analyze Kurisu's laptop, Rintaro decides to tell Maho the truth about time machines, warning her that she mustn't attempt to use one herself to save Kurisu. The group become surrounded by a hostile group who take Maho hostage, demanding the laptop in exchange. However, another group appears and destroys the laptop, leaving Maho upset that she couldn't protect Kurisu's legacy. Later, Maho and Alexis return to America, bringing Rintaro's time with Amadeus to an end."

"Kagari collapses again after hearing Mayuri singing a song, which Rintaro believes may be a hint to regaining her memories. He finds that Mayuri had learned the song from Suzuha, who herself had learned it from Yuki in the future. Yuki then reveals she had learned the song from Rintaro's mother, who claims he was the one who sang it to her back when he first started his mad scientist phase. While visiting Mayuri's grandmother's grave for any clues, Kagari goes into a daze upon hearing a song on the radio and almost gets hit by a truck, after which she regains her memories of Mayuri being her mother. It is then revealed that Rintaro had learned the song from Kagari herself years ago, when a mysterious organization spotted her."

"Despite Kagari regaining her childhood memories of Mayuri, who is informed about her future relationship with her, Rintaro and Daru remain curious about what happened during the past twelve years that she still doesn't remember. During an argument with her, Suzuha notices a contradiction in Kagari's recollection of their seperation, with Tennouji suggesting to Rintaro that it may be the result of brainwashing by a third party. The next day, Rintaro goes with Moeka to investigate an abandoned building located near where Kagari was found, discovering it to be a secret facility where Kagari was being held captive. Meanwhile, as Kagari heads towards a party held by Mayuri, she hears a song that causes more memories to resurface, at which point she starts hearing a voice and disappears somewhere."

"Shocked by a surprise attack, Suzuha and Daru look to America as their last hope to save the world."

"Fed up with her Dad's passiveness, Suzuha must make a man out of Daru before Yuki ends up with somebody else."

"Okabe's stubbornness causes fists to fly and tears to be shed as the deadline for using the time machine swiftly approaches."

"As Suzuha sets off to finish her mission, Mayuri finds determination of her own. But then, disaster strikes."

"All hell breaks loose over the time machine when a villain from the future haunts the past and unveils their devious plan."

"War and disaster has come, and the only way Okabe can stop it is to rely on his friends, determination, and hope."

"Okabe awakes in a cold, lifeless world where he finds his friends struggling to survive amidst all the chaos."

"Setting forth on a long and arduous journey, Okabe seeks to rekindle his hope and revive what all had thought gone."

"In their struggle to save the time machine, the lab members brainstorm to circumvent convergence but realize it cannot be done without sacrifice."

"Okabe and his friends must battle against fate in the past, present, and future to find Steins Gate and reunite the lab members once and for all."