Unopened Book and the Supreme Treasure

Unopened Book and the Supreme Treasure (開かずの書と至高の秘蔵品) is a game event in Mass for the Dead that was released on July 31, 2024 to August 14, 2024.
==Background==
When Shalltear visits the library, Ashurbanipal, the librarian shows her a book that seems to be locked and cannot be opened. After learning that the book was left behind by her creator, Peroroncino, Shalltear tries to open it at all costs, but...Unopened Book and the Supreme Treasure Episode 0: Prologue
== Incident ==
An undead librarian at Ashurbanipal receives a rare visitor in the form of Shalltear Bloodfallen to the library. Shalltear has brought, having found it in her room, but has no recollection of the item, so she would like to know if the librarian knows anything about it. The undead asks to see the item, which the Floor Guardian complies and gives it to the undead.
He attentively examines noting it's exquisite cover and wonders perhaps it was left behind by some Supreme Being. Externally it looks like one of the books in the library. Oddly the undead finds that he cannot open it, as if there is a lock. Shalltear knows about this hence why she came to the librarian hoping for some answers. It doesn't seem that the pages are glued together, but the undead librarian wonders what kind of tampering has been done.
The undead thinks if it should use [Appraisal Magic Item] to determine what kind of book it is, but while examining the metal cover, the book starts to glow to the surprise of the vampire and librarian. The librarian believes it is an illusion created by magic, but as it continues to glow, the librarian becomes startle. The glowing light depicts Peroroncino's crest.
A few hours after the incident at Ashurbanipal, at the 9th Floor in the Bar, at the counter seat there was a customer the establishment normally did not see: Aura Bella Fiora. However the dark elf is not at the bar for drinks, but came at Shalltear's request, as the other female Floor Guardian wants to ask her something.
And so Shaltear tells her friend about the book she found deeply hidden in her luggage. But more than anything she is unable to read the contents of the book and doesn't know what to do. Aura hearing that the book belonged to a Supreme Being, is curious of contents of the book. Before she can think more on the discovery, Aura remembers that the protagonist' will soon return for a meeting at the Round Table Room for a regular report. When Shalltear asks what of it, Aura suggests that they should ask the protagonist for advice as he might be able to give her some good ideas. 
The vampire is hesitant to talk to anyone else about Peroroncino's book, although Aura pointed out that it's too late as she told her about it. Shalltear drunk and depressed over the issue, and the time of the culling the Chaos Beasts at the Throne Room, Aura to drag the vampire out of the bar, much to the relief of Clavu restoring the serene atmosphere. 
A few days later at the Round Table Room, the protagonist is leading the meeting with Momonga and the Floor Guardian over his reports. Shalltear present at the meeting cannot help but think how flawlessly the homunculus is carrying out his duties. On the current issue, the protagonist brings up the deciphering of secret letters seized from criminal and intelligence organizations within the Kingdom, E-Rantel, and the surrounding countries. But so far progress isn't going as smoothly as they have hoped. Shalltear who is listening recalls that the deciphering of secret letters was being done as part of intelligence gathering and analysis.
Momonga engrossed in the report from the homunculus, wants to hear more asking what the problem is. To which that while it is not uncommon for secret letters to be sent in code, recently people have been becoming more vigilant, and the methods of concealment have become more sophisticated. It seems Nazarick's methods of deciphering so far have not worked, and they are now currently looking for a solution to the problem, but so far have not yet found an effective one. In layman's terms they are can't crack the codes of the letters.
The Overlord knows the protagonist better than to sit on a difficult problem and asks what the next step will be. The protagonist would like to gather information at Ashurbanipal and remain in Nazarick to conduct some research. Seeing that there is no reason to not allow it, Momonga accepts his request. The conversation on deciphering codes suddenly hits Shalltear with an idea of using a "cipher." Unopened Book and the Supreme Treasure Episode 1: An Unexpected User
At the conclusion of the meeting, the protagonist and Slimeko are heading to the library, as it has been awhile for the latter to have visited Ashurbanipal and hopes everything is alright. The protagonist is a little worried, but is sure the librarians there are busy with their work in the stacks and their own duties. The pair plan to head to the library to do their research though the homunculus feels that the research isn't worth bothering.
They are called out by Shalltear who appears running towards them in the corridor. The Floor Guardians has something urgent she wishes to discuss. The Nazarick field agents are given the details of Shalltear's problem. Now having the full picture, the protagonist deduces that Shalltear wants to research on cryptography after hearing him talk about codes earlier in order to open the mechanism on the book she found. Given the importance of the item, Slimeko understands the urgency for Shalltear. The pair are happy to assist the vampire in the endeavor. But since they will also be doing research at Ashurbanipal they will have to do this project in between.
When the protagonist's party arrived at the library, he went to talk to the librarian about the shelf where the material he was looking for was located. The protagonist notices that there are some books that he can't find in the places he remembers them being. He wonders if their classification has changed, the ones concerning codes and how to decipher them. The librarian apologies as the books were collected by the undead to a nearby shelf along with some stories based on them. This was done in response to the current situation after being advised by Demiurge that they would be needed. 
The protagonist is thankful for the help, and hopes that there is material for beginners as it would be great if there were an easy way to understand code-breaking. After making sure Shalltear and Slimeko were somewhere away, the protagonist whished a question to the librarian, on a specific book, which the undead quietly directs him to a shelf next to the cryptography material. The protagonist goes to retrieve before return to his colleagues ready to begin. 
However Shalltear raises a question about asking where the materials for their research are, asking what kind of work the librarians do, unaware that the material had already been gathered previously. Since Shalltear is totally ignorant of what a librarian does the undead calmly explains that the job of a librarian is to handle lending and returning books and organize the shelves. And also recommend book that suit the tastes of their users and assist them in researching and gathering information. 
While Shalltear processes this information, the protagonist adds that Ashurbanipal has a huge collection of books, and there are many people who se it on a regular basis, so they have to be careful when dealing with the books. Hence why the library staff have to maintain confidentiality. A librarian's job is to help gather information, but in order to do so, it is absolutely necessary that they do not leak information about users. If, for any reason, this were not kept, then the relationship of trust which is a prerequisite for gathering information, would not even be possible. 
On this the protagonist compares a librarian's job to be the same as conducting intelligence matters, as the job involves "information transactions" with trust as a basis. Because librarians do not abandon the other party, they can be trusted with sensitive information. The librarian states that is correct as in order to fulfill their role of helping users find the books they are looking for, they ask for only honesty about any information, even if it may be a little embarrassing to share with others. To achieve their roles, they need trust to ensure that no leaks will happen. 
However, this would not be the case if someone were to appear seeking disturbing information that would bring harm to Nazarick. The librarian seeing Shalltear interest, wonders if the vampire wanted to know someone's usage information. The undead tells the vampire, then reminds them that they should take a look at the materials they requested. The protagonist complies and leads the group to the stacks. Unknown to them they are followed by an unknown silhouette figure. 
The group then begins collecting the materials at a table to read. The unknown figure is revealed to be watching them from a corner of the library. The figure turns out to be Momonga, invisible under the spell of [Perfect Unknowable]. He finds the presence of Shalltear being with the protagonist and Slimeko to be unusual so he stealthily approaches the table to eavesdrop on their conversation. 
Shalltear going through the piles of books, recites that a "code" is a way of managing information by hiding it. According to the protagonist there are two main methods chosen to conceal communications: "hiding" or "converting" the content. The former involves writing down the contents of the communication in an inconspicuous place, or hiding the letter amongst somethin that at first glance seems unrelated. 
Shalltear asks if slipping a letter inside a book or shoebox would count which the protagonist confirms. Momonga listening in, remembers how Peroroncino, had once passionately talked about a scene in a school story where a love letter is hidden in a shoe locker. However Shalltear feels that such a method could mean that someone unrelated could find the letter, which the protagonist also agrees as if a third party finds it, the purpose of "hiding" will be defeated and be a failure. 
As for the "converting" method, there are various methods. For example, there is a "code cipher" that replaces words or set phrases with different symbols or character strings according to predetermined rules, and a "cipher" that replaces individual letters rather than words or phrases. "Cipher Codes" can be further divided into "transliteration" and "substitution." By using these conversion methods, the contents of the communication cannot be understood when read in the normal way and this is what is called a "cryptography." 
Another query is asked on if it applies to something like a "password." The protagonist states that is correct though for passwords it's common to use words. In the case of codes, they can be used for long documents such as letters, so they are a bit more complicated. Momonga hearing this remembers that there were people who used long sentences as their "password." 
For the protagonist he goes on to say that the person reading the code must either understand the code's conversion rules or know a method of decryption based on the conversion rules. Also, it is common to not disclose the conversion rules or decryption methods to outsiders. 
To start, the protagonist asks to examine Shalltear's book. The book in his hand, the protagonist had heard from Shalltear that the cover had the word "Secret" and Peroroncino's crest would appear on it. But since the book won't open, if there is a code hidden in it as Shalltear believes, a clue must be somewhere on the cover. He soon notices something, to which Slimeko inquires what he found. 
The protagonist shows his friends that the decoration on the cover, has a pattern on the border. It probably modeled after musical scores, so it could be a clue to the code. Shalltear thinks that this might indicate some secret letters using the musical score symbols. That in mind, the protagonist thinks that the documents they seized from the outside, included something like a conversion table, which could be worth studying. 
Momonga watching is impressed that the homunculus managed to explain something as complicated as code in a way others like Shalltear could understand. Having been engrossed in listening, Momonga glances at the code written on the cover of the book, wondering what it could be. However his reaction is immediate in that he experience emotional distress and shock. He had almost forgotten that such an item existed as recognizes it. The Overlord remembering his purpose to the library, quickly sneak away.Unopened Book and the Supreme Treasure Episode 2: Information Research 
Momonga returns to his office, dispelling [Perfect Unknowable]. He was not able to retrieve the book he wanted at the library, but now has encountered something unexpectedly shocking while browsing in Ashurbanipal. He refers to the book that the NPCs were studying. It involved an incident that happened in the past during the time of Ainz Ooal Gown, a guild of heteromorphs. It was on that fateful day was Momonga casually conversing with Peroroncino and his companions at the Round Table Room. 
Peroroncino had bought some additional data to the annoyance of his sister Bukubukuchagama as she can't believe he wasted money again. Momonga, then the guildmaster, is more conciliatory as Peroroncino has been searching for this particular data for a long time. This doesn't make Bukubukuchagama feel any better as she feels that the guildmaster is spoiling her younger brother too much. 
The data turns out to be additional content for an erotic game Peroroncino has been addicted to. Peroroncino got in touch with a fellow player, who also plays YGGDRASIL, and started making new costumes for characters based on the ones that appear in the erotic game. And while there are issues with rights, it just similar externally, and is feels content that his request was worth it and managed to get his associate to sell them to him. 
Peroroncino even has a sketch of a swimsuit that the player made. Due to copyrights issues, the costumes are worn by original characters, but the accuracy of the reproduction of the key points are excellent. After all he declares that the theme is "The Strongest Beautiful Girl on the Beach" and believes its perfect for Shalltear, the strongest Floor Guardian, so his purchase was a must. 
Bukubukuchagama hearing this tries to get a word with her brother, but his nonstop excitement on dressing his NPC, irritates her to no end that she finally gets his attention by shattering the table to the shock of everyone in the room. Now having his full attention, Bukubukuchagama calmly asks Peroroncino what the title of that erotic game he was. This only draws puzzlement from Peroroncino on why she is angry as he is not trying to make her NPCs wear anything weird, before Bukubukuchagama repeats her request again. 
Back in the present Momonga recalls that Bukubukuchagama had been offered a voice role in the game that her brother was addicted to, but had to drop out due to various problems. She wasn't angry at Peroroncino, but at an unpleasant experience she had with the production company that was involved with the game. Still seeing her mad was really scary to Momonga. After that Momonga helped Peroroncino in tampering with the costume he bought so Bukubukuchagama wouldn't get mad. And for extra measure warned the rest of the male members in the guild. 
The book Shalltear had at the library, looks similar to the exterior of the data collection of the completed costume design. Even if it wasn't that, Momonga thinks that there must have been a lot of secret data among Peroroncino's possessions that were pretty risqué, right on the edge of what YGGDRASIL would allow. So it's possible that the one piece of data ended up in Shalltear's room. 
A few hours later, Momonga is in the Round Table Room, receiving the protagonist and Shalltear. He learns from them that there is a good chance that the problem of deciphering the secret letter can be solved. Among the other material seized by the Sorcerer Kingdom was a document that appeared to be a conversion table. At the time of discovery, Nazarick had not yet determined how to decipher it, but after examining materials in Ashurbanipal, the protagonist was able to find several possible methods of conversion. 
Momonga commends the protagonist for his research, however the homunculus modestly claims that neither he nor Slimeko could have fully gained an understanding of the information at this time. In fact Shalltear had been most helpful. This comes as a surprise to Momonga to hear that Shalltear has been cooperating. 
To explain why the Floor Guardian was assisting the homunculus and slime in decoding a secret letter, she gives him the story about Peroroncino unopened book, leaving Momonga troubled. The vampire informs her master, that she has determined that the music-like sheet decorations on the cover is a code, and is trying to decipher it. 
Momonga realizes that this is what Shalltear was researching at the library. He understand Shalltear's interest in the book, given it's a relic left behind by her creator who is like her parent and having a desire to open it. What he doesn't understand is why Peroroncino would set up a code on the book in the first place. While thinking this, he says aloud that he guesses that everyone has secrets they want to keep to the shock of the two NPCs. 
Upon hearing him say well done to Shalltear and how he was surprised to see her helping the protagonist in his investigation, it leads Shalltear and the protagonist think that Momonga knows the true nature of the book left behind by Peroroncino. And that this was an opportunity to make them act independently. Momonga seeing this, realized that they have misunderstand him again. 
After the meeting, Shalltear, the protagonist and Slimeko are seen walking in the corridors of the 9th Floor. The protagonist plans his next step to compile the findings and then return to E-Rantel. He asks what Shalltear intends to do in which the Floor Guardians plans to decipher the code in her free time and continue researching in Ashurbanipal. Slimeko says if the protagonist will be compiling his results for his investigation, then that means they will be staying in Nazarick for a few more days. If that is the case, maybe he could help Shalltear with the decryption. The protagonist considers this and agrees to lend some aid to Shalltear much to her joy.Unopened Book and the Supreme Treasure Episode 3: Things You Want To Keep Secret 
The protagonist and Slimeko find themselves in Ashurbanipal to once again try to decipher the code on the "musical score" on the cover of the book they borrowed from Shalltear. On a desk, in addition to the book they borrowed from Shalltear, there were numerous stacks of papers and documents which the protagonist conferred and flipped through whist jotting down notes. After a series of this was repeated, the protagonist finally stooped and leaned back in his chair. He finally was able to see that the code on the cover is in the form of a "musical notation," but somehow knows how to understand the pattern. All that is left is whether or not he can decipher it using that pattern. He thinks that the notes on the sheet are letters, either a combination of consonants and vowels. 
A few more hours had passed when the protagonist finally put down his pen and declared he figured it out. Slimeko is glad as Shalltear should be returning from the hunt of the Chaos Beasts. Shalltear arrives in short order, and the homunculus informs her of the news that he has deciphered the code. This thrills Shalltear, although the protagonist warns her that he is not sure if the deciphered content is correct. So they will need to check it first using Shalltear's book. 
The protagonist then recites the code: "Seek and Desire"...."She is the muse that colors the beach"..."She is the most beautiful girl on the beach"..."You are"..."The strongest". Immediately the book cover flashes, and the lock unclasps. Shalltear wastes not time in opening and flipping through the pages. What she sees astonishes her, the book contains drawn pages...an art book containing pictures of a human woman in a swimsuit. There is a piece of paper stuck between the pages with something written that resembles a floor plan which Shalltear thinks is of her room. 
A few days after the code was deciphered, the protagonist and the others returned to Nazarick for their regular report. On the way to the Round Table Room, the undercover adventurers are met by Shalltear, who wants to speak to them privately. They relocate to the Guest Room where Shalltear then tells her friends that she searched the closet in her room based on what was written on the paper in the book. What she found was a hidden space at the back of the closet, which contained several unfamiliar swimsuits. 
The swimsuits she found were the same as the ones depicted in the pictures of the Peroroncino's book. Turns out one of the swimsuits is of the "Strongest Beautiful Girl on the Beach." It looks like Peroroncino had create the code on the book to hide the swimsuits. But the protagonist cannot fathom a reason why the Supreme Being would go to all this effort and hide a near unreadable code just to him a swimsuit. 
Although he keeps this question to himself, and expresses how amazing the item was well hidden to Shalltear especially with the encryption on the cover. The Floor Guardians agrees, and while she cannot understand her creator's mind for doing so, she has no doubt the equipment he left behind is for her. That brings her down to the next request she has. The protagonist sees that Shaltear wants the protagonist to help her test of the power of the new swimsuit as if she could understand the item's power it could help increase her fighting power and broaden the scope of her tactics, which the protagonist would be more than happy to help.Unopened Book and the Supreme Treasure Episode 4: The Contents Of The Secret Book
At the Round Table Room, Momonga is surprised about Peroroncino left behind a "swimsuit". He is told about Shalltear and the protagonist's investigation into the book that belonged to the birdman led to their discovery of several swimsuits in a secret compartment in Shalltear's room.
The book while containing many pictures of a young woman who appeared to be human and was called "the most beautiful girl on the beach", strangely enough---is the new swimsuit that Shalltear found was apparently the exact same one as the one in the picture. Momonga examining the book, comments to himself that he expected as much. The book was the collection of costume designs that Peroroncino mentioned in the past. Though it looks like he went to the trouble of setting a code so it couldn't be easily seen and also put that note inside with the hidden cache of swimsuits. If he had to guess Peroroncino never thought the code would be cracked.
The two NPCs had a discussion and would like to ask for permission from Momonga to "try out" the swimsuit that was left behind by Peroroncino in actual combat. Momonga who has been covering his face due to the shame of knowing Peroroncino's real story of the swimsuit stash is dumbstruck when the request is made. There are several swimsuits, so Shalltear would like to try them all if possible, but for now she would like to try one or two first.
Especially the swimsuit of the "Strongest Beautiful Girl on the Beach" which is is sure is not just any equipment. Momonga quivering in embarrassment though knows actually called the "beach's strongest," but he doesn't think it's really suited for combat. Even so he keeps it to himself. So he tells the NPCS that the request is sound as just like the swimsuits that have been using on missions thus far, it's possible that these new swimsuits possess some kind of power.
But at the same time tries to subtly discourage testing the equipment, adding that perhaps however, the reason why Peroroncino made the code and kept it secret was...maybe it's not for use as combat equipment. If something were to happen to them he wouldn't be able to face Peroroncino. While Momonga does not like to lie to them, he thinks it's best to stop.
His persuasion fails, as while Shalltear appreciates the concern, because this equipment was left behind by Peroroncino for her, she wants to make it useful toMomonga...and to Nazarick! Hearing this Momonga is disappointed his words have fueled her enthusiasm instead of stopping her. Seeing that he cannot dissuade her, he permits it, on one condition, that the trial is strictly for personal use. Therefore, it cannot be used in large-scale athletic meets. As for the testing site, he wants it to be at the Crack on the 6th Floor. Excited Shalltear thanks her master and goes to prepare. Momonga then tells the protagonist and Slimeko, to accompany Shalltear and try out the swimsuits and they will see for themselves whether they can withstand real combat.
On the 6th Floor some distance from the Amphitheater, Aura calls over the arriving trio. The homunculus apologizes for not coming quicker, but the dark elf tells them that they had plenty of time before the appointment. Both Slimeko and Shalltear are dressed in the new sets of swimsuits. Shalltear was worried that they would have been late while they were changing. Aura curious asks what the vampire was doing that would have made her late. The protagonist though deflects the question, stating it's nothing for Aura to be concerned about. But secretly tells Aura, when changing into her swimsuit, Slimeko felt embarrassed to be wearing a treasured item of the Supreme Being.
The four then begin walking into the forest to the Crack. Aura comments to the other women that they both look good in the swimsuits, as what they are wearing are definitely Peroroncino's treasured possessions.
Slimeko feels honored. Shalltear tells her what she is wearing is same as a picture that was drawn in Peroroncino's book. Apparently, the theme of the drawing was "The most beautiful girl on the beach." Aura hearing the word "strongest" thinks that indicates that the item is quite powerful. That is what the group are trying to find out and Shalltear is sure of. Still Aura wonders why there was nothing written about the items effects. And winders maybe even if it was written, she couldn't read it properly, but dismisses this as the vampire would have read Peroroncino's book in detail.
Aura tells Slimeko she not be so embarrassed, and her nervous reaction is understandable as it's equipment left behind by a Supreme Being. This makes the slime feel better. There is a reason for why Slimeko was allowed to wear the swimsuit. Shalltear wanted to confirm the meaning of the note that was with the swimsuit, "For Slime Girls." There were also a few other swimsuits with notes with the names of Slime girls attached to them. She wonders if there are characteristics that suit each race, or if there is some deeper meaning hidden within but she would like to investigate this further with the help of others when she has time. They come to the Crack, just when it is about to release Chaos Beasts. As the monster come out the group then prepare for battle.Unopened Book and the Supreme Treasure Episode 5: The Meaning Of The Secret Book
== Aftermath ==
After the Chaos Beasts are destroyed the women celebrate their defeat. They, minus Aura, report to Momonga back at the Round Table Room. This comes as a surprise to Momonga that the swimsuits are battle-proof. But since Peroroncino hid it in code, Momonga had thought it would have some effect, but it was even more effective than he expected.
Although the trio only looked at two of the swimsuits this time, the protagonist thinks it would be well worth looking into the rest of the swimsuits. If that's the case, Momonga thinks it might be a good idea to continue testing it on the 6th Floor for a while, and then use what works for in missions.
Shalltear has no objections and would like to express her sincere gratitude to Momonga for having been given the opportunity to experience Peroroncino's kindness. The vampire wonders if the reason Peroroncino went to the trouble of making password and trying to keep it a secret was so that he could entrust the swimsuits to her. The fact that he went to such lengths means that he considers Shalltear important to him. To repay Peroroncino's kindness, Shalltear will do her best to be of even greater use to Momonga! Although Momonga thinks that a better description of Peroroncino's actions was that he was probably "hiding" them than "entrusting"...but he guesses if that's what she thinks it's okay. 
And thus, the matter of the unopened treasured book in Shalltear's room was resolved for the time being. Meanwhile in Momonga returns to his office, thinking back to the swimsuit Shalltear had found. No matter how Momonga looks at it, the "strongest beautiful girl on the beach"...isn't exactly equipped for combat. What Peroroncino was talking about was simply equipment that resembled swimsuits from erotic games...and it's not something that has anything to do with combat in terms of the genre.
But according to the results of [All Appraisal Magic Items] and Shalltear and the others' reports, that swimsuit seems to be able to withstand combat well. At first he thought it was just Peroroncino's preference -- a swimsuit without a data crystal inside, just the exterior. Although it looks like the designer prioritized appearances, it looks like it's built with valuable data crystals that can withstand a pretty serious battle, nothing less of what he expected from Peroroncino.
Well, either way Momonga is glad Peroroncino wasn't here. He can't imagine what Peroroncino would think if he found out that the NPCs knew about this. No the only ending Momonga can imagine is one in which he faints in agony. Apparently the creator was careful not to violate copyrights, and Momonga doesn't think the NPCs will notice that it's based on an erotic game.
In view of this experience, Momonga finds it's really important to keep secrets...if they are revealed in the wrong way, it will become a real credibility issue. Having been reminded once again of the importance of "information" and "trust" in a completely unexpected way, Momonga gently clutched his stomach, which should no longer be there. No one here, or even within Nazarick for that matter, knew his true intentions.Unopened Book and the Supreme Treasure Episode 6: Secrets Are Beautiful
== References ==
Category:Events
Category:Mass for the Dead Events
Category:Incidents