Luvia explains that she booked her participation in Fen’s Casa in advance, but Sion called her to the Library of Alexandria so she asked Shirou to take her place just so the 1 million euro fee would go to waste. Ruolong explains he’s on a mission from Ziz to find Shirou and learn how to win the Casa. He asks if Ptolemy told Ergo he’s Alex 4. Ergo’s identity reveal begs the question of who is Ruo but he doesn’t answer beyond “his best friend”. Ruo proposes they work together until they find Shirou. Rin and Luvia are more well-informed about Shirou while Ruo is more well-informed about Monaco’s mafia, not to mention Ruo has still not recovered from Gray’s seal. The mafia group hunting Shirou is called Morte. And since the enemies are seemingly trained by the Mage Killer, Luvia finds it relevant to reveal to Rin and Ruo that his name is Emiya Kiritsugu.
Van-Fem provided one bedroom for Flat and Ergo and one for Waver and Gray.
In the boys’ room, Flat tells the story of how he met Van-Fem. Flat was out of a place to live because his parents started siccing assassins on him. Fem found him while he was fighting the 3rd assassin (a curse hitman fused with a caterpillar), recognized Flat as Messara’s descendant, and took him to live in his place. Flat empathizes with how Ergo also had his life threatened because of his father. Ergo can tell that Flat uses magecraft to regulate his expressions. Flat tells the story of how Waver also saw through that and explains his views on the El-Melloi Classroom as a welcoming home to all its students. Lastly, Flat talks a bit about his dream of summoning and befriending a Servant one day. His list of examples includes Iskandar, Jack the Ripper, and Saint-Germain. Ergo confides in Flat about his memory status and asks for advice. Flat doubts the premise that his memory saturation is a side effect. Ergo losing all of his memories could be what Wuzhiqi or Ziz truly need to achieve their goal. Ergo asks if there’s anything Flat can do to stop this, but unfortunately, Flat’s analysis only parsed 20-30% of the spell, so the two boys agree on the only solution currently available to them: Flat installs a bomb to kill Ergo when he loses all his memories.
Meanwhile, in the other room, Big Sis Gray worried that Flat could be a bad influence on Ergo. Waver returns from the veranda after sending Flat’s bird familiar to find Rin and Luvia since they aren’t answering their phones. Gray is still kinda sick, so Waver makes dinner for her. Gray has a big moment of quiet introspection because learning that Waver can cook comes with the realization that her years taking care of him were never a necessity, it was all so she wouldn’t be without anything to do when she was to start her new life in London. Meanwhile, the awkward professor only knows how to talk about their personal situation through lectures on how the act of cooking is regarded in mage culture. Waver received a Casa participation card. His participation card is a Tarot card, The Fool, but Van-Fem is a silly fellow, so his design for The Fool is a chibi alligator holding a clock.
15 minutes before the first game, Sizhen visits Waver’s room to suggest a team-up in the Casa and leaves a card with her phone number. The clock hits 9 PM, so the alligator in the card explains the rules of the first game: only 3 players are allowed to join Van-Fem's dinner table, so the first challenge is to get there. The room’s doors and windows are all locked. However, Waver can still call Flat. Flat already explained to Waver before but now he explains to Gray that Fem’s Casa comes in 3 kinds.
1) Authentique, where everyone plays a regular casino game like roulette or poker.
2) Magique, the draw of the Casa, where players connect their Magic Circuits together to play an arcane game.
3) Nouvelle, where the trend-loving Van-Fem tries out new trends.
This opening just now proved this game to be a Nouvelle game with Fem trying out escape rooms. An hourglass spawns giving them a time limit below 20 minutes. Waver opens his participation card and
both parts have a Humpty Dumpty scene hidden on the inside. The summary won’t include all the trial and error, but the solution to the puzzle is that Humpty Dumpty’s lyrics mention four scores of men trying to return Humpty to his place, one score is 20, and 20 is a corner bet in European roulettes, so Waver needed to command Ergo and Flat to make corner bets in the roulette they had in their room, spin 4 times, and return the ball to its original position. Solving the puzzle opens secret staircases in both rooms. The puzzle requiring their specific team composition implies Van-Fem invented a different puzzle for each player. Gray has a moment of catharsis, going over her feelings of genuine enjoyment for the first game, celebrating how she’s finally in a challenge purely meant for entertainment rather than a life-threatening situation. But it doesn't take long for the other shoe to drop.
The staircases lead Gray, Waver, Ergo, Flat, Ithillid, Sizhen, and Azel all to the same hall. Everyone talks, confirming all puzzles were different. Ithillid finds traces of body temperature telling another player solved his puzzle before everyone else and has already left the hall. The group heads to one of the cruise’s VIP rooms, where they all discover Ziz’s dead body.