While attempting to figure out what had happened, the remaining guests discover that their radio is not working, effectively leaving them stranded on the island with the culprit until the typhoon passes. They also quickly discover that Kinzo has gone missing as well. Battler and the rest of the family come up with the theory that one of the eighteen people on the island is posing as Beatrice in an attempt to claim Kinzo's inheritance. The three primary suspects are the servants, who have access to the entire mansion; Natsuhi, who was the last person seen with Kinzo; and Eva, who has the most to gain from the murders. However, after a heated argument between Natsuhi and Eva, they are unable to come to a definitive answer and return to their rooms. Later, Eva and Hideyoshi are found to have been murdered in their locked room.

Everybody tries to determine how Eva and Hideyoshi could have been killed when an odd smell begins to fill the mansion. Kanon goes to investigate the boiler room along with Kumasawa, but is mortally wounded in the process. The rest of the family and staff arrive and discover the dying Kanon, as well as Kinzo's partially incinerated body. They decide to retreat to Kinzo's study, which should be the safest room in the house. After they enter, however, a letter from Beatrice mysteriously appears. Since Genji, Nanjo, Kumasawa, or Maria are the only possible suspects for planting the letter, Natsuhi forces them to leave the study. Later that night, the phone rings with Maria singing on the other end. Natsuhi, Battler, George, and Jessica rush downstairs to find Genji, Nanjo, and Kumasawa murdered and Maria standing in the corner, still singing.

Rosa's siblings and their spouses go missing, while the remaining guests find the chapel door locked. Finding the key inside the envelope Beatrice gave Maria, everyone enters and find the missing people murdered inside, along with some of Kinzo's hidden gold. Jessica and Kanon are ambushed by Beatrice, who summons her legion of goat servants against them. Kanon fights off the goats until Beatrice summons two Stakes of Purgatory, Asmodeus and Satan, who kill Jessica and Kanon. In Purgatory, Battler and Beatrice suspend their game to determine how the first six people could have been murdered inside a locked room. Battler begins forming several theories, but Beatrice counters most of them, using red text to speak the truth. However, Battler manages to catch Beatrice off guard by theorizing that the culprit could have taken the key from the envelope, locked the dead bodies in the room, and put the key back where it was. Beatrice congratulates Battler, but remains confident he will submit.

Everyone finds Jessica's body in her locked room, while Kanon's is nowhere to be found, having been erased by Beatrice. After the notion of Kanon killing Jessica is deterred since he gave Jessica his master key, the other servants are marked as the most likely suspects. Battler, meanwhile, finds himself unable to think of any way the crime could have been carried out while knowing the servants are innocent. Rosa sends the servants off, hoping to use them as bait to draw out the culprit. In the process, the servants stumble across Kanon, severely wounded but apparently still alive, who tells them that Rosa was the one who attacked him. However, it is soon discovered that this Kanon is a duplicate created by Beatrice. The fake Kanon attacks the servants, killing Nanjo and Kumasawa before being destroyed by the other servants.

Rosa recounts how she met the human Beatrice confined in a hidden mansion, Kuwadorian, on the island twenty years ago and helped her escape, only to see her accidentally fall off a cliff to her death. Beatrice confirms to Battler that she truly died as a human, and that there are currently no more than 18 people on the island, forcing Battler to accept his loved ones as possible culprits. Genji, Shannon, and Kanon are later summoned to Kinzo's study, where they see Beatrice offer him as a sacrifice and kill him. Kanon is pit against the seven Sisters of Purgatory, defeating Lucifer in a duel, though he and Shannon are overwhelmed as they try to fend them all off at once, prompting Genji to euthanize Shannon and Kanon before he is put to rest by Ronove. The Sisters search the mansion for more sacrifices, killing Gohda in the process. They find Kumasawa as well, who claims to have been waiting for Beatrice. Beatrice reveals Kumasawa to be her predecessor and teacher, the former Beatrice.

Eva is discovered by Rosa and leaves to discuss how Kinzo's gold should be divided among the siblings. The young Eva, however, refuses to share the gold and remains behind, declaring herself to be the head of the Ushiromiya family. Acknowledging the young Eva's achievement, Beatrice appears and dubs her the new "Beatrice", whom Battler deems to be an alter ego for the real Eva. Later, Eva falls ill, and Rosa takes a whining Maria outside to spare Eva from her tantrum. They are suddenly attacked by Eva-Beatrice, who repeatedly kills and resurrects them in bizarre ways. Beatrice takes pleasure in the scene, but ends up enraging Battler, who refuses to play with her any longer. Dejected, Beatrice confronts Eva-Beatrice and mercifully kills Rosa and Maria once and for all, ordering her successor to act more dignified and reasonable in the future.

Battler decides to give Beatrice another chance to change her ways, so Beatrice goes to the real world to visit George, who is still grieving over Shannon's death, and offers to bring Shannon back to life. However, her powers have greatly diminished, but with George's assistance, she manages to resurrect Shannon. Sensing this, Eva-Beatrice kills George and Shannon shortly after they reunite, along with Krauss and Natsuhi in the process. Shortly after the survivors discover the bodies, Jessica accuses Eva of being the culprit. Eva panics and accidentally fires her rifle at Jessica, blinding her with the muzzle flash. While Nanjo escorts Jessica away to treat her, Jessica insists he go back to keep Battler out of danger, but Nanjo is killed by Eva-Beatrice before he can, leaving Jessica completely defenseless.

Ange briefly withdraws from Beatrice's game to confront Maria over her denial of being neglected by Rosa, but Maria tells her that she is content with Sakutaro ensuring her mother's love. Beatrice decides to show Ange how she, upon noticing how Maria created a soul for Sakutaro, gave a human body to Sakutaro and named Maria the Witch of Origins, joining forces with her in a witch's alliance called Mariage Sorcière. Ange recounts how she too was once a member of this alliance and learned how to summon the seven Sisters of Purgatory, becoming close friends with Mammon in the process. By the year 1998, however, she loses the ability to use magic, and continues her investigation of the Rokkenjima murders. Before she returns to the game, Ange is confronted by Lambdadelta, who tells her that if Battler defeats Beatrice, he will return to her past self in 1986 while her current self will remain alone, and proposes that Ange can remain with her brother if he continues to fight against Beatrice for eternity.

In 1998, Ange interrogates relatives of the Rokkenjima murder victims and hires a boat captain to take her to Rokkenjima, discovering Sakutaro's torn remains as well. In 1986, the cousins are informed of Kinzo's test from the hostages in Kuwadorian and are forced to lock Gohda and Kumasawa in the storehouse to keep them from interfering. Jessica and George are individually tested by Ronove and Gaap, respectively, and instructed to choose which of the islanders will be next to die: themselves, their true loves (Shannon for George and Kanon for Jessica), or everyone else. Jessica chooses herself for Kanon's sake so that he may live his life to the fullest, while George chooses everyone else as he is willing to go so far for his love for Shannon to be accepted. Unwilling to leave the hostages in the dungeon, however, Jessica and George defiantly engage their respective demons in combat.

In 1998, Ange arrives at Rokkenjima and continues on alone with Mammon and Sakutaro, only to be ambushed by Kasumi and her men, who proceed to beat and taunt her mercilessly, and destroy Maria's diary. Noticing that Kasumi is being manipulated by the spirit of Eva-Beatrice, Ange miraculously summons the Sisters of Purgatory despite the large amount of magical resistance present, killing Kasumi and her men. Before vanishing, Eva-Beatrice resurrects the long-dead, human Eva to shoot and kill Ange, though Mammon destroys her gun, allowing Ange to kill Eva and make peace with her own emotions towards her. Ange meets with Bernkastel, who confirms that she is nothing more than a piece in the game between Battler and Beatrice. However, Ange remains determined to save her family.