Beatrice and her predecessor have an all-out magic battle, much to Battler's disbelief. The morning after, the first twilight victims are discovered. As the survivors move to the guesthouse, Eva begins solving the epitaph.
Beatrice is standing in the rose garden with her furniture, being scolded by her predecessor, who's gotten tired of her killing innocent people; the Endless Magic is not intended to be used this way. Beatrice tries to justify her actions, saying it's just a way to stave off boredom, but the Predecessor is unmoved by this and asks Ronove to clear everyone out of the way. As he and the Stakes stand back, the Predecessor then announces she'll be taking back her name and the title of Endless Witch from Beatrice.
Beatrice is unwilling to comply, and sparks of magic clash between the two witches and explode, leaving a smoldering crater. Beatrice is unfettered by her teacher's abilities, remarking that she'd have to destroy the entire island to defeat her; at her command, a pair of Shoulder Towers emerge from the ground behind Beatrice and fire upon her teacher. The Predecessor creates a barrier with her wand to block their attacks, and retaliates by summoning a massive spear, the words "Smothered Mate" appearing on-screen. Realizing the danger, Beatrice sends away her Shoulder Towers and summons an army of giants; the Predecessor is unfazed, saying that mere giants cannot block a spear of the gods. Calling upon the Disciples of Hephaestus, Beatrice orders her giants to create a shield that can block the spear. The giants protect Beatrice as her teacher throws her spear, which disappears after hitting the shield. Beelzebub watches in awe at how Beatrice managed to block the Divine Spear, and Ronove corrects her, saying that she merely avoided it. Beatrice peeks through her shields to see that the Predecessor is gone; she's now above her, and launches more Divine Spears. Unprotected, Beatrice becomes impaled and pinned to the ground as her familiars disappear; the Stakes watch in horror as Ronove comments on the Predecessor's abilities. The former Beatrice alights and proclaims her victory. She begins reciting a spell to return Beatrice to her original form, asking her to remember. Beatrice reminisces on how long it's been since they last sang together; her teacher continues the spell and Beatrice sings along with her, telling her teacher to remember the things sticking in her back.
The Predecessor soon realizes that she's been pierced with spears; the other spears pinning Beatrice disappear, and she explains that she actually summoned four Shoulder Towers. The other two Towers appeared behind the Predecessor and killed her as soon as the battle started; Beatrice revived her instantly and played along. The Predecessor falls over dead as Beatrice mocks her, digging her foot into her head. In the metaworld, Battler is bewildered by the entire spectacle, unsure of how he can deny the witch now that he's seen such crazy magic. Beatrice and Ronove arrive, with Beatrice overjoyed at her victory; Ronove asks Battler for a counterattack, but he can't come up with anything.
At 6:00 the next day, the adults end their conversation, having stayed up all night to consider every move Beatrice could make. Natsuhi suggests getting breakfast and taking a break. As they leave the dining hall, they pick up on a strange smell. They then see blood seeping out from under the parlor door, with a strange symbol drawn on it. Eva reports that no one is in the kitchen, and Kyrie and Rudolf say that a similar symbol was drawn on the boiler room and was locked; the weird smell is probably coming from there. Hideyoshi tries the parlor door, and that is locked as well. Worried for the cousins, Hideyoshi, Rosa, and Natsuhi go to the guesthouse while the others search throughout the mansion. The cousins turn out to be safe; Krauss goes to speak with Kinzo but gets no response, noting how the servants are nowhere to be seen as well. Eva notes that there are magic circles drawn on several doors, and were all locked while Natsuhi reports that a bunch of keys in the servant room are gone.
Hideyoshi, Rosa, and Kyrie return from the guesthouse with Nanjo; they look through the parlor window to see Shannon sitting inside. Hideyoshi tries to get her attention, but she doesn't respond. The other adults soon arrive, with Krauss using a rock to break the window. He reaches inside to unlock it, and the group soon finds that Shannon is dead, with blood around her.
Battler sits in the arbor in the metaworld, lamenting how there's seemingly nothing he can do against Beatrice. The Predecessor arrives, and Battler is surprised at her presence, citing how she should be dead; she explains that she's just a piece that has been taken and removed from the gameboard. The Predecessor offers to teach Battler a little bit about magic, explaining that Japanese magic involved a rain ceremony with fire; Battler explains that it's not magic because it's scientifically proven: fire creates an updraft to cause rain clouds to gather. The Predecessor then says that the ancient people believed that it was magic, and Battler comes to understand that if one doesn't know the principles behind something, then it's basically magic. The former Beatrice gives another example, saying that cathode-ray tubes in a TV are powered by gremlins using magic; Battler dismisses it as nonsense, to which she asks why he denies it if he's never looked inside one. She adds that, until they look inside the tube, both their magical explanations and scientific explanations can exist at the same time. The Predecessor then brings up Schrodinger's Cat, asking if the cat in the box is dead or alive. If you open the box, you'll learn the answer; until you open it, both can be accepted as truth.
In short, Rokkenjima has become just like Schrodinger's Cat: Battler is seeing the murders from the magic side of things, and has been trying to come up with the logical side of things. Battler finds this idea hard to grasp since, if two truths can coexist, can you really defeat your opponent in an argument? The Predecessor adds that he's already been defeated, which is why he surrendered. Battler laughs, and asks for the former Beatrice's name; she no longer has one, but she settles for the name Virgilia. Virgilia offers to help Battler in his game against Beatrice, with him finding it ironic that a witch is helping him deny witches. He accepts her proposition, thinking that it'll help him save everyone on Rokkenjima; he then announces that he'll avenge her, and returns to Purgatorio.
Beatrice greets him back, asking what he thinks of the fantasy battle; Battler claims there was no battle, seeing no sign of the towers and spears that she used. He compares it to the cathode-ray tube, explaining that since the rose garden is currently empty, this means nothing at all happened there. Beatrice realizes that he's talking about Schrodinger's Cat as Ronove calls it a "Multilayered Worlds Contraction Technique", the power of a Finite Witch. Virgilia soon appears, announcing how she's assisting Battler.
The clock is at 7:00. The survivors are gathered in the guesthouse, with the adults loading Winchester rifles. Rosa says that the source of the smell was Kinzo's corpse, found in the boiler room burnt; his extra toes are proof that it's him. Back in the metaworld, Battler accepts that he must accuse one of the 18 as the culprit. He asks Virgilia to reconstruct the first twilight: she explains that Shannon was the first victim found, her corpse in the first floor parlor; the doors and windows were all locked, making it a closed room. Battler asks Beatrice to clarify what a closed room is, with her explanation being that "all ways in or out of a particular room are completely sealed. Not only is intrusion from outside impossible, it's also impossible to intervene from across that boundary." She wants to refer to it from now on as "Beatrice's closed room definition"; Shannon's room fits that definition.
Virgilia continues, saying that Shannon's corpse had a single master key on it, found by the relatives. Upon request, Beatrice reiterates that there are five master keys, one for each servant. Next to Shannon's corpse was a letter containing the key to the second floor guest room. That room was also locked, with a magic circle drawn on it. Using the key, they found Kumasawa's corpse inside; she also had a master key, and the letter nearby contained a key to the third floor waiting room. Inside there was Gohda's corpse, again with a master key and a letter containing the key to the second floor VIP room; Battler realizes that it's a chain of locked rooms.
The second floor VIP room had Genji's corpse, with a single master key; the letter contained the key to the boiler room. The boiler room had Kinzo's corpse, the letter containing the key to the chapel. Finally, the chapel had Kanon's corpse, with the last master key and the key to the parlor. The linked closed rooms formed a single closed room, with every master key and individual room key locked inside it.
Beatrice explains that murder from outside these rooms was impossible. Battler asks if traps were involved, and she states that none of the six were killed by a trap. Battler then theorizes that the culprit was one of the six people; Beatrice finds it ridiculous, saying that she already confirmed the deaths of everyone in red. Battler reasons that if one of the six locked themselves in a room and committed suicide, this closed room can be solved; Battler asks to repeat that "all of the six were killed by other people." Beatrice thinks for a bit, but refuses to repeat it, looking flustered. Battler sees her refusal to repeat it as resignation, and pronounces checkmate; Beatrice stops him and confirms that none of the six committed suicide.
Beatrice relaxes as Battler is surprised that she could say it; Virgilia says it's a trick, as Beatrice changed the sentence he wanted to repeat. Battler thinks some more, and realizes that one of the deaths was neither homicide nor suicide. He then reasons that the culprit was among the victims, and wanted to hide or escape after constructing the closed rooms, but then accidentally killed someone. Beatrice starts to repeat something in red, but Ronove stops her; he requests that they receive some time to strategize. Virgilia grants their request and they disappear, with Battler looking disappointed.
Meanwhile, the adults are resting as Eva sleeps, a notebook with the epitaph open in front of her. The younger Eva is asking if she's giving up on her dream of stealing the headship from Krauss; Eva mumbles in her sleep, finding a certain line of the epitaph to be difficult. She asks what a sweetfish river is, and her younger self tells her to think of something similar. Eva thinks about it, and wakes up with an epiphany; Hideyoshi sees her and asks what's up. Eva says she's going to wash her face, but goes to the library in the guesthouse instead. She searches through the shelves for a book, finding it and pulling it out; she flips through and figures out the meaning of the sweetfish river, quoting the line "if you go down the river, you will reach a village." Eva then has more realizations, assured that she's solved the epitaph.
Soon after, she walks down a stairwell, reaching the bottom and finding a door with the line "on the tenth twilight the journey will end, and you shall reach the village of gold" written in red on it. She goes through and finds herself inside a bedroom. After turning on the lights. Eva then sees a pile of gold; it really existed after all.
Virgilia narrates the preview, speaking in a cheery voice and branding it as "Big Sis Virgilia's Life's Troubles Advice Corner." She reads out a letter coming from Natsuki in Saitama Prefecture:
"They say Madame Beatrice has lived for a thousand years. Virgilia was her teacher, so of course she has to be even older than that. Which brings me to my question-how old are you? You couldn't really be a ten-thousand-year-old fogey, could you?"
Virgilia stops reading the letter, taking offense at the word "fogey." She says the next episode title and continues in her cheery voice, saying that she's seventeen years old in witch years.
|0:00||1:29||Katayoku no Tori||Katayoku no Tori||Opening|
|1:30||2:20||N/A||N/A||Beatrice and her predecessor have a chat|
|2:40||3:55||Fake Red Shoes||Umineko no Naku Koro ni ~Rose Crimson~||The witches engage in battle|
|5:06||5:50||Waltz Op. 34||N/A||Beatrice emerges victorious|
|6:58||9:20||N/A||N/A||The first twilight murders are discovered|
|10:34||12:18||N/A||N/A||Battler and the Predecessor talk about Schrödinger's Cat|
|12:40||13:26||Core||N/A||Battler determines the witches' magic battle never happened|
|13:56||16:37||N/A||N/A||Virgilia reconstructs the first twilight|
|17:10||19:08||Suspicion||N/A||Battler theorizes over the first twilight|
|19:19||20:41||N/A||N/A||Eva's younger self encourages her to solve the epitaph|
|21:07||21:44||N/A||N/A||Eva discovers the gold room|
|21:45||23:14||la divina tragedia||la divina tragedia~Makyoku~||Ending|
- In chess, positional plays are where you try to build up your own territory while limiting the enemy's.