The episode opens with Rem and Ritsuka in Rem's limousine on their way to school. Rem asks Ritsuka if she really hasn't changed her mind about staying with him. She replies saying she will be fine because her brother will be returning from England tonight, so she will stay at her friend's house in the meantime. Rem insists that she will be safer in his mansion as they arrive outside the school. When they alight from the limousine, Ritsuka gets a bit tensed to be seen with Rem. She quickly thanks him and dashes off with embarrassment. The other students begin gossiping about her and Ritsuka is desperate to clear up the misunderstanding, but she finds herself unable to. Her thoughts are interrupted when Azuna appears exclaiming her name. She rushes up to Ritsuka and embraces her with relief, saying she was worried. Ritsuka assures her that she's fine and as they walk down the hallway, she tells Azuna that she takes back what she said about Rem the previous day. When Azuna asks why, Ritsuka explains that she called Rem a jerk, but after he helped her last night, her opinions of him have changed.
During class, Ritsuka cannot help thinking about her current lifestyle after the events from the previous episode. As she glances around the classroom, her classes are the same as it was yesterday; but as for herself, her life isn't normal anymore. When lunch comes, Ritsuka is told by a male student that she has been summoned to the 'Third Library' again. Azuna offers to accompany her, but the male student tells her she can't come because they only asked for Ritsuka. Ritsuka thanks Azuna and assures her that she'll be fine as she follows the male student to the 'Third Library'. Once she arrives, she is greeted by Roen who scurries up to her. She asks if he also came to school and starts petting him on the head much to his delight. Urie interrupts by holding his rose in front of Ritsuka's face, startling her. He tells her that they meet again as he takes her hands to pull her back onto her feet much to her embarrassment and Roen begins to act all hostile. Urie introduces himself and he tries to persuade Ritsuka to leave Rem, and to come to him instead for help. He tells her that if she is with him, he'll definitely make her heart pound like crazy but Ritsuka backs away from him.
Shiki appears and tells Urie to stop messing with Ritsuka. He introduces himself and tells Ritsuka that he's heard what had happened to her from Rem. Shiki asks her if she is alright and to come to him if she needs anything. Ritsuka appears relieved until Shiki tells her that thinking about what might've happened to her makes him shudder with excitement. Mage appears and grabs Shiki by the shoulder, telling him to back off. He tells Ritsuka that Shiki is being a creep as usual before grabbing one of the sleeves of her school blazer and tilting her chin upwards. He introduces himself and tells her to come to him instead for help, but Ritsuka pushes him away. Mage tells to not be shy and assures her that he'll definitely protect her, but she clearly turns down his offer. Urie and Mage start bickering and Shiki tells Ritsuka that those two are always like that, but he is interrupted when Roen bites his leg. Shiki grabs Roen and asks him if he wants to be put to sleep. Rem shortly appears ending the bickering. He informs Ritsuka that he was just on the phone with the police. They have tracked her mother's phone in the Nagano Prefecture, near Karuizawa.
He asks Ritsuka if this information rings a bell, and she replies that her deceased grandfather's house is there. When she mentions that his research materials on devils and vampires are there, Rem suddenly takes her hand and he tells her that they're going to Nagano immediately. He convinces her that they might be able to find a clue to where her mother was taken. Ritsuka agrees to go and she texts Azuna to inform her that she won't be joining her for lunch, which makes her friend concerned. In the 'Third Library', Mage mutters how annoying it is that Rem took Ritsuka along with him when he could just go by himself. Urie says that Ritsuka might hold a clue that she doesn't know herself and Mage comments that the 'Arlond heir' sure has it rough, but Shiki sternly reminds him that Rem is known as 'Kaginuki' in the human world. Meanwhile, in Rem's limousine, Rem asks Ritsuka if she hasn't eaten lunch yet. A bento feast is laid out between them, but she replies that she doesn't feel hungry, but Rem tells her that she must eat even at times like this.
Ritsuka reluctantly agrees and she eats a tamagoyaki. She exclaims that it's delicious and she thanks Rem for helping her again, today and yesterday. Rem says he hasn't done anything to earn her thanks, but Ritsuka insists that he has done a lot for her, so she is very grateful. She then attempts to start a conversation with Rem by asking him if he likes dogs. Ritsuka reveals that she saw Roen in the 'Third Library' earlier on and Rem bluntly responds, saying that Roen just followed him to school today. He tells her to not start a pointless conversation and they resume eating until Ritsuka notices him picking out shiitake mushrooms from his sushi roll. She asks him if he dislikes them which he denies, but it amuses her. They eventually arrive at her grandfather's house, only to find that it has been ransacked. Rem warns her that whoever did this may still be there and they enter the house. The state of the inside reminds Ritsuka of how her own house had been overturned in the previous episode and she starts frantically searching each room for her mother, but to no avail. Rem suddenly spots a cell phone and shows to Ritsuka who recognizes it as her mother's, realizing that Maria was at her grandfather's house.
She starts to tear up prompting Rem to place a hand on her shoulder while assuring her that they will find her mother. They go to the living room and Ritsuka tells Rem that the "grimoire" is a book of magic, a powerful one. She says that her grandfather kept a lot of books and files on his research, but does not recall him having the "grimoire". As she starts clearing up, Rem asks her if she knows where else may her grandfather store his materials, but Ritsuka says she doesn't know. She then tells Rem that in her younger days, she would often go to her grandfather's house during the holidays with her mother and brother. Rem spots some photos hanging on the wall and he asks her if the people in one of the photos is her mother and grandfather. Ritsuka confirms this and mentions that the last picture on the wall is her mother's sister and her maternal aunt, Marta. Rem asks her if Marta would know anything about the "grimoire", but Ritsuka sadly replies that her aunt passed away when she was still a baby. Rem tells Ritsuka to not be so concerned about the mess, telling her that he will get his servants to fix it up. They start to head out, only to find out that they've been locked inside when Ritsuka fails to open the door.
Rem asks her about another entrance from the kitchen, only to be interrupted when they hear burning noises. They find one of the rooms on fire and Rem attempts to smother out the flames using the curtains until Ritsuka remembers that there is a fire extinguisher. She dashes off to fetch it despite Rem's protests and she finds the extinguisher in the kitchen. Just as Ritsuka attempts to retrieve the fire extinguisher, one of Jek's minions grabs her hand from behind. This startles her and she attempts to resist, but the minion pulls her into his arms and places a hand over her mouth to silence her. Luckily, Rem appears and throws a kick at the minion, prompting him to release Ritsuka. Rem places a protective arm around her and pulls her closer to him. He spots the exit and instructs Ritsuka to get out of the house immediately. When she hesitates, he tells her to go and when she leaves, the minion ignites a lighter and tosses it onto the floor. This sets the kitchen on fire, trapping both him and Rem. Seeing this, Rem scoffs and says; 'You call that fire?'
The minion duplicates into four minions and Jek appears. Rem sings 'I'm Rem Arlond' ("Wagana wa Rem Arlond" 我が名はレム・アーロンド) as he single-handedly fights the minions. He tells them that Ritsuka is his as he uses his powers to disintegrate them into dust, but Jek escapes. He pins one of the minions against the wall and he asks him if he's found the "grimoire" yet. When the minion doesn't respond, Rem takes this as a 'no' then annihilates him. Outside, Ritsuka is accompanied by Rem's chauffeur and desperately hoping that Rem is alright. She suddenly hears Rem's voice reassuring her and when she looks up, she spots Rem exiting the burning house unharmed. Upon seeing Rem, she rushes up to him while tearfully saying that she's relieved he's alright and she addresses him by his name for the first time (she previously called him Mr. President). Rem appears slightly surprised and touched by this, but he steps back from her and brushes her off cooly. While the police and the firefighters take care of her grandfather's house, Rem and Ritsuka head back to Shikō Town.
Ritsuka falls asleep in the limousine, so Rem instructs his chauffeur to take them back to his mansion immediately. By the time they return to Shikō Town, it is already nightfall. As Rem's limousine pulls up outside his mansion, Ritsuka awakes. She peers out of the window and spots her brother, Lindo, waiting outside the mansion gates. As she rushes out to greet him, Rem's eyes slightly narrow. Ritsuka happily welcomes Lindo back home and with a gentle smile, he assures her that everything will be fine now that he's here. Rem steps out of his limousine, but he doesn't appear to be pleased to see Lindo. When Lindo sees Rem, his eyes narrow, becoming a glare, causing Ritsuka to get slightly tensed. The episode ends here.