|Please! You have to listen to me! He didn't kill her! His heart is screaming that he didn't kill her!|
On the day before the HAT-1 rocket launch, an international spy known only as "the phantom" infiltrated the Cosmos Space Center with two aims: to sabotage the launch and to destroy a psychological report on him. His first task was easily carried out, with a bomb that he had planted on the rocket damaging many of its critical systems upon detonation. To complete his second aim, he went to the Center's robotics lab and stabbed Metis Cykes (who had created the psych report) with a katana displayed on her wall. In order to ease his planned escape, the phantom took Cykes's GYAXA uniform jacket, using its built-in ID tag to fool the Center robots' recognition systems, and ornamental Noh mask. Athena Cykes, Metis's daughter, then arrived at the lab to find her mother lying dead on the floor. Athena grabbed a knife from a tool box and stabbed the spy in his hand, thereby causing some of his blood to splatter onto a nearby moon rock.
After knocking the girl unconscious, the phantom was forced to escape the Cosmos Space Center before he could be discovered and leave the bloodstained moon rock behind. In a childlike state of denial and not really understanding the difference between humans and robots, Athena had Ponco move Metis to the robot disassembly table, thinking the machinery would be able to "fix" her like it did the robots.
At that moment, Metis's student, prosecutor Simon Blackquill, arrived. Athena, covered in blood from the ordeal, explained to him - with a "sweet smile" and a "far-out look in her eyes," as Blackquill later recalled - what she intended to do. Blackquill, thinking that Athena had killed her own mother, used the murder weapon, Metis's katana, to forcibly dismantle Ponco, before removing Athena and the pieces of the robot from the lab. By the time Athena had returned to the Center, Blackquill had been arrested for Metis's murder.
Blackquill's trial was held soon afterwards. Athena tried to speak out in his defense, saying that "his heart is screaming that he didn't do it," but she was ignored because no one understood what she meant. Blackquill pleaded guilty and was soon convicted, leaving Athena traumatized by the ordeal and causing her to repress many of her memories of that day.
After Blackquill's verdict was announced, a traumatized Athena was sent to live in Europe. Wishing to save Blackquill, but not knowing how, Athena eventually decided to become a lawyer after meeting former defense attorney Phoenix Wright. She was also determined to use analytical psychology for the task, which her mother had specialized in, but being ignored during her previous ordeal in court would cause her to suffer panic attacks when reminded of the incident and subsequent trial; the true events of her mother's death would be suppressed in the form of black Psyche-Locks.
Meanwhile, Aura Blackquill - Simon Blackquill's older sister, and close colleague of Metis Cykes - was devastated by the incident, having had her colleague/mentor murdered and her brother put on death row. She became embittered, antisocial, and nursed a deep hatred for Athena and the legal system for supposedly taking away those dear to her.
Alongside Wright's disbarment a year prior, the UR-1 Incident helped to usher in the so-called "dark age of the law". Allegations of false charges and fabricated evidence abounded, and public opinion and confidence in the legal system were at an all-time low. Seeking to resolve this, Miles Edgeworth decided that he needed his old friend Wright's help again. Thus, while the Prosecutor's Office continued their investigations, Edgeworth pulled a few strings to allow Wright to successfully retake the bar exam and regain his attorney's badge.
- Main article: Turnabout for Tomorrow
On December 20, 2027, Aura visited her brother Simon at the detention center. With only one day remaining and her brother refusing to attest to his innocence, Aura took drastic measures to protect her brother. Organizing her robots, she took a group of visitors hostage at the Cosmos Space Center, including Phoenix Wright's adopted daughter Trucy. Aura demanded that a new trial be held, and indicted Athena as the true culprit behind Metis's murder. With all the other courtrooms occupied, Wright was forced to defend Athena in the ruins of Courtroom No. 4 (which had been destroyed in a bombing), Edgeworth as the presiding prosecutor and Aura observing the proceedings via Clonco. By this point, Athena had become convinced that she had murdered her mother.
However, Wright eventually proved the innocence of both Athena and Simon. Simon was cleared of all charges, much to the joy of Aura. While she was subsequently arrested for her hostage taking, Aura nevertheless thanked Wright, Athena, and Apollo Justice for proving her brother innocent. Edgeworth permitted Simon to take over as prosecutor for the case, while he continued to search for more information regarding the phantom. Wright, Athena, Justice, and Simon would go on to reveal that the phantom had been watching them while disguised as police detective Bobby Fulbright.
- To date, this case's retrial has the second youngest alleged first-degree murderer in the entire Ace Attorney series, the youngest being Ahlbi Ur'gaid, who was accused of Paht Rohl's murder in The Foreign Turnabout at only 9 years old. Although Ur'gaid and Machi Tobaye in Turnabout Serenade are younger characters chronologically, Athena was only 11 years old at the time of her mother's murder, whereas Tobaye was 14 at the time that Romein LeTouse was killed.
- This case bears some similarities to the DL-6 Incident. In both cases, the victim's child believed they had accidentally murdered their respective parent, when in actuality they had only wounded the real killer. In addition, the primary suspect for each case was innocent, although one was convicted and the other acquitted.
- Of the modern-era's alphanumerically named cases, the UR-1 Incident is the most recent to occur, taking place in 2020 and after the events of the original trilogy.