The Legend of Heroes: Trails into Reverie/St. Astraia Case Files~Myka and the Beautiful Swordsman

St. Astraia Case Files~Myka and the Beautiful Swordsman (女学院の事件簿～マイカと麗しの剣士～) is an episode in. Its events take place prior to the main story.

Background
The episode can be accessed from the Infinity Corridor.

Synopsis
At St. Astraia Girls' School, a student remarks about how dull life has become after the Great War ended. As she takes a nap, she is woken up by two students. The student's name is Myka Brighton, who is Wayne's little sister. The two ask her about Wayne and if she can introduce the two to him, since the Thors Branch Campus students helped in ending the war. Myka tells them that her brother is an out of shape muscle-head only interested in fighting. She expresses a desire to see his friend Stark; since the war ended, they haven't been able to get photos of Rufus Albarea and Cedric Reise Arnor. The two students wonder if she is fooling around and if she has been affected by the "Coma Incident". Myka shows no interest and becomes upset at having to go through another three months before noticing some people outside.

Outside are Juna Crawford, Musse Egret, Elise Schwarzer and another girl with long, blue hair. They arrive at a scene where Juna asks for the details; a girl had collapsed in the middle of broad daylight. Elise asked the guards if anyone suspicious was around, but they did not see anyone. Elise is unsure as what is causing the situation, as six girls have already collapsed. Elliot Craig soon comes in, being one of the "helpers" for the case. Elliot has been working at the school as a temporary music instructor and hopes he can get the girls back to normal with his music. He then notices the blue-haired girl and chuckles awkwardly.

A few days prior, Elise informed Class VII of the situation - Juna, Musse and Kurt Vander. Elise asks them to keep the situation confidential. Because the school only allows girls in as students, Kurt opts to stay outside, but Musse ropes him into getting in by disguising him as one of the students, much to his disdain, making Kurt the long haired girl. To further avoid suspicion, they went to Eryn to get a voice-changing potion. Kurt temporarily takes the guise of Clusia and wishes to finish the investigation so he can get back to normal.

Elliot suggests there is either a leak or someone is maliciously spreading chemicals around. Since there is not enough evidence to support either claim, he suggests they split up to investigate both of them. Myka then walks in and offers to assist, having heard of the incident and willing to help, albeit she just wants to get closer to Kurt. As Elise leaves, Myka accompanies Juna and Kurt to the rooftop where one of the incidents occurred. Kurt deduces that the culprit must be one of the students.

In the music classroom, Elliot and Musse find two students playing. They ask them about the coma incident, and the students tell them that the middle school students had been cleaning up when one of them inexplicably collapsed. They also tell them that an upperclassman had told them that another student had collapsed during class, contrary to the belief that it occurred during break or after school.

Back with the other group, Myka tells them that the floor they're on only has a single classroom and storage room, but no incidents had occurred. She also reveals she found the ring around here; she had asked the Student Council to locate its owner, but they were unable to, so she kept it. As the bell rings, Juna and Kurt leave to meet up with Elliot and Musse. Myka then begins wondering where she found the ring and that her memory is getting fuzzy; she tries to call them, to no avail.

In the Student Council room, the four discuss their findings. They are unable to find anything, prompting Elliot to consider a third option - the occult. Linked to the Artifacts, he suspects that one of them might be causing the incidents, and that all of them were affecting middle school students. Elise then enters the room and asks them if they saw Myka. Myka did not head to class, which prompted her teacher to inform Elise in turn. They head to the storeroom and find a strange portal. To ensure no one else enters, either Elise or Elliot choose to remain behind while the other joins the three to investigate.

Upon entering the portal, they find themselves in the Gral of Erebos once more. Musse suspects that this part of the Gral was not moved alongside the rest. As they head deeper, the aura intensifies. Myka realizes she had found the ring here, but her memory is fuzzy. As she comes to, she wonders where she is when her ring goes off and spawns Yyd Vanas, one of the Seventy-Seven Devils, who was feeding off the girls' energies. The group arrives before the demon can harm Myka, Kurt and the others arrive. Myka notes that Clusia's voice is different, but Kurt apologizes for deceiving her.

The group eliminates Yyd Vanas, prompting the space to begin collapsing. They escape the segment and return to Elise, who recognizes the ring as the school's namesake. Called the "Ring of Relief", it could heal anyone by simply having the user holding the target's hands. The group suspects that Yyd Vanas had been sleeping the entire time but only woke when the Great Twilight began; in an imperfect state, it used Myka to protect it until it could recover. Elliot points out that demons have made use of artifacts before, and offers to bring it to Gaius Worzel when he has the time.

The following day, the same two students from before call Myka. Myka wonders why Kurt was disguised and is upset at the Goddess for deceiving her, before remembering that he is a man. Prior to the group's departure, Kurt realized that Myka was Wayne's little sister and thanked her for trying her best. Myka realizes that Kurt is both handsome and smart. While she has to live up with the boring monotony of school life, being introduced to Kurt has made her life more exciting.