Eternal Library & Criminal

 is the twelfth chapter of the Trinity Seven manga series, released on December 8, 2011 in the Monthly Dragon Age January 2012 issue and later compiled in the third volume on April 5, 2012.

Summary
On a stormy night at the Royal Bilbia Academy in an empty hallway, the glasses on the windows suddenly shatter while a young girl with twin tails silently smirks as she walks by.

Meanwhile, Arata comments on the weather inside his dorm room when Lilith unexpectedly arrives and informs him of an incident.

Afterwards, Lilith and Arata, along with a gathering of students, stare in shock and awe at a hallway with broken windows. Akio and Mira also arrive, with the latter stating that she senses traces of a Breakdown Phenomenon. Arata denies any involvement while Yui, making an appearance, also confirms the presense of strong magic. While Lilith chatises Yui for being close to Arata and teasing her, Arata asks Yui if she caused another Breakdown Phenomenon. Yui rebuts his claim, pointing out that if she had, the school would have turned into a dungeon or a black sun would have appeared for Arata. Mira reaffirms Yui's statement, although she also mentions to Lilith that the magicbears resemblance to a certain library. Lilith, realizing Mira's suggestion, also agrees with her suggestion.

Later, Arata, along with Yui, questions Arin of the library Mira and Lilith were referring to as Yui does not recall anything due to being asleep. Levi suddenly appears and states that ghosts have appeared, frightening Yui. Arin then begins recalling of a ghost incident where on one day on a stormy night as well, a pair of twins were researching alone in the library until the windows shattered and books avalanched without warning. After the disturbance, the older of the twin had disappeared as well and had since been missing for half a year before Arata's arrival. However, there had been some accounts from witnesses who claimed to have seen the missing girl. Upon hearing the story, Arata decides to also investigate the scene.

Arriving at the library along with the girls, Arata encounters Lilith and Mira investigating as well. Although Mira initially resists his involvement, Arata manages to persuade them as he is capable of stopping a Breakdown Phenomenon while Akio is asleep. Arata then notices Selina and queries her the reason for her presence. But before she can answer, the group is abruptly transported to an unknown abandoned location. Mira and Lilith transforms into their Magus Mode as Mira confirms the location is the Eternal Library much to Liltih's surprise. Akio also awakens as a result and suggests the rest of the group to gather around to avoid getting in their way. Around the same time, Selina requests Arata to stop groping her while a jealous Yui reproofs him before warning him of a sudden surprise attack. Selina manages to help him avoid the assault by pushing him out of the way. When he regains focus, Arata notices the appearance of a girl bearing great resemblance to Selina. Both Lilith and Mira are surprised after recognizing her as Lieselotte. Lieselotte, after greeting them, then attempts to steal their magic until Levi and Akio intervene. The new girl greets them happily as well as Akio guesses that she had turned into an evil Magus. Selina explains to a confused Arata that Lieselotte is her older twin sister and the girl who vanished as a ghost. Lilith also adds that she is a criminal who conducted an experiment to connect to the forbidden Eternal Library. Moreover, Mira further states that Lieselotte is the former second seat of Grimoire Security and Selina lastly reveals that her sister is the Trinity Seven of Acedia (Sloth). Lieselotte, delighted by the presense of the Trinity Seven and a Magic King Candidate, declares that she will steal their magic.

Characters

 * Arata Kasuga
 * Lilith Asami
 * Arin Kannazuki
 * Yui Kurata
 * Mira Yamana
 * Akio Fudo
 * Selina Sherlock
 * Levi Kazama

Introduction

 * Lieselotte Sherlock

Trivia

 * Lieselotte's identity as the missing last member of Trinity Seven was first hinted in Chapter 10.