La Baleine (lit. "The Whale") is a large Astermite-powered airship frequently used to transport citizens into Paris. La Baleine is quite expansive, being large enough to house hundreds of travellers, while also providing services to entertain and accommodate passengers - such as in-flight doctors, cafés, and areas lit by street lamps in which passengers can stroll about and engage in the scenery through a large front-facing observation deck. La Baleine is also a part of the recent movement to replace coal-burning technology with Astermite in order to reduce emissions; powering La Baleine lift generators, street lamps and likely other technology aboard the airship.
Upon making contact with Vanitas alongside the discovery that she had become a Curse-Bearer, Amelia Ruth boarded La Baleine in order to meet Vanitas in Paris so that he could properly treat her condition with The Book of Vanitas.
Alternatively, Noé Archiviste, after receiving a letter from The Master informing him that The Book of Vanitas was rumored to be in Paris and that he needed to discern its true nature, also boarded La Baleine.
With the recent outbreak of attacks by Vampires on humans by the Nine-Fold Murderer, Thomas Berneux, the gossip spread among the humans on board La Baleine - many of whom believed Vampires to be all but extinct. As Noé listens to the gossip from afar, he notices Amelia waver, as she appears to be unwell. As she falls, Noé rushes to her side and catches Amelia in his arms, asking her if she's alright.
Noé brings Amelia to a café, where she thanks him for his kindness as they enjoy some tea together, though Noé tells her not to worry about it, and asks if she's certain she is all right with him not bringing her to the doctor's office. Amelia however claims that she should be fine with a little rest. Moving in frighteningly closer to Amelia, Noé examines her and objects that she has a poor complexion, which worries him. Amelia just shrugs it off and states that it's just her anemia, asking that Noé not worry about it, while promising that she'd go see a doctor later. Upon noticing Noé's confusion, Amelia sips her tea and admits that she has no intention of seeing anyone other than her doctor - Vanitas - for a variety of reasons - thanking Noé again for all his help.
Amelia then notices something out of the corner of her eye. Just then, Murr - Noé's cat - jumps out from underneath the table toward Amelia - prompting Noé's order for Murr to behave. As Amelia sits and pets Murr, she gushes about how cute and warm he is. Turning back to Noé, Amelia introduces herself asks Noé's name in return. Noé, misinterpreting Amelia, assumes she means the cat - and so he introduces Amelia to Murr - however before Amelia can object, the captain of La Baleine announces that they'd be arriving in Paris in about an hour.
Hearing this, Noé rushes to the window to look for Paris as they grow nearer and nearer to the city. Growing anxious when he's unable to see it, Noé asks Amelia where Paris is. When people begin to notice Noé's odd sense of excitement as he rushes around La Baleine, Amelia subtly tells Noé that she doesn't think that they can see Paris yet from the airship, which disappoints Noé. Despite this, Noé voices how amazing he thinks it is that one could reach Paris in the blink of an eye aboard an airship like La Baleine. As Noé giggles with excitement, Amelia asks if this is the first time that Noé has ever rode on a dirigible, prompting Noé to ask what gave it away. Noé explains that he's always been confined within the forests of Averoigne, so this is his first time seeing and riding in such a large airship, carrying on about his astonishment over how something so heavy can float through the sky and how he's heard that Paris rivals London in terms of steam mechanisms; hence his looking forward to arriving in Paris.
Curious, Amelia asks if Noé is going to Paris to do some sight-seeing. Unexpectedly, Noé grows more serious and proclaims that his purpose in Paris is to find something calls The Book of Vanitas. Noting the shock on Amelia's face, Noé asks if she's heard of it, explaining that it's the name of a cursed book that introduces the fairy-tale about Vanitas of the Blue Moon; which Noé then elaborates on.
Out on the roof of La Baleine – Dante asks if Vanitas is really going in, which Vanitas confirms – as they know that the target is inside and he’s not about to let it get away.
As the clock tolls, Noé voices his surprise that it’s already so late. Picking up Murr – who gnaws on Noé’s sleeve – Noé states that they’re going to have to get ready to leave La Baleine soon enough, and offers to walk Amelia back to her room. Amelia agrees passively, though she’s notably distracted as she can only focus on how cold she feels. While Noé walks Amelia back to her room, Amelia asks if Noé truly believes that The Book of Vanitas exists. Noé says that he’s unsure, but he’d recently received a letter that detailed The Book of Vanitas’ presence in Paris from his master. Thus, whether or not The Book of Vanitas is real, Noé must journey to Paris to verify it.
Suddenly, Amelia collapses once again, but as Noé attempts to help her, Amelia tells him not to touch her – her reaction causing a light nearby to shatter behind Noé. Murr hisses at Amelia as she rises, with Noe finally realizing that Amelia is a Vampire as her eyes turn red and she bears her fangs. With that, Vanitas crashes through a nearby window – glad to have finally found Amelia. As Vanitas lands in front of them, Noé cradles Amelia in his arms. Intrigued, Vanitas claims that he’d thought it’d be easy to catch her, but asks what Noé’s part in this is. Turning the question around, Noé adds that the same can be said for Vanitas – who reveals that he’d only come for Amelia and that it’d be within Noé’s best interest to just put her down, suggesting that he’ll get hurt if he doesn’t. However, Noé refuses, only to have Vanitas immediately retaliate with his knife.Though Noé is able to dodge enough of Vanitas’ attack, he falters soon enough, as Vanitas notes that he can’t move effectively while carrying Amelia. Vanitas then clicks a button on his knife, transforming it into a whip. As Vanitas continues to pursue Noé and Amelia, Dante comes in through the broken window and questions what’s going on with Vanitas’ weapon.
Not long after, Vanitas manages to knock Noé off balance as he struggles to deal with Amelia, sending Amelia flying into the air. While Vanitas and his Partner believe that they’d won, Amelia stops mid-air and floats above them – confusing Vanitas long enough for Noé to retaliate and throw Vanitas into a nearby wall before catching Amelia. While Noé makes off with Amelia, Dante rushes to Vanitas’ side, asking if he’s still alive. Standing, Vanitas laughs at his own carelessness – as he should’ve known that Noé was also a Vampire by his red eyes. Vanitas asks Dante to hurry, stating that based on what they’d just seen, they don’t have much time.
As Noé carries a barely conscious Amelia, Amelia voices repeatedly how cold she is. Within her mind, Amelia sits along in a warm field with flower petals floating all around her. Amelia then notices someone out of the corner of her eye – a black figure who gushes about how warm it is there, how pretty Amelia’s flowers are and how he likes it there – asking that Amelia give that place and her name to him. As the creature puts its hands on Amelia – she’s consumed by the darkness flowing out from it.
As Amelia screams, Noé delivers her to one of the officers aboard La Baleine and requests that she be taken to a doctor immediately. The officer asks what Noé intends on doing now – prompting Noé to explain that he intends on finding the one who attacked Amelia and having him explain what exactly is going on. Hearing this, Amelia springs forward and wraps her arms around Noé, telling him not to go. Suddenly, Amelia starts panting – while she thinks of how it’s so cold that she could die, which is why she desires something warm. Amelia then sinks her teeth into Noé’s neck, consuming his blood – which frightens the passengers observing the situation. As Noé drops to his knees he thinks of how much his strength is fading and forces Amelia off of him.
Amelia remains frozen in the air, dripping black tears from her eyes and chest as she grows more and more thirsty for blood. Amelia realizes that the blood made her feel warm again, and so she insists that Noé give her more of his blood, summoning shadowed thorns from the black tears pooling on the floor. Amelia sends the shadowed thorns after the human spectators and lunges at one of her victims – only to be stopped by Noé – who asks that she stop what she’s doing, as Vampires are not allowed to attack humans and if she continued to do so she’d be disposed of. It is at this moment, with Amelia in his grip, that Noé realizes that he can’t move his body properly and that it was likely due to poison from Amelia’s bite.
Just as Amelia is about to kill Noé, Vanitas intervenes – casting her away and standing in front of Noé to keep him protected – reminding Noé that he’d warned him about getting hurt. Vanitas announces that, just as he’d thought, Amelia’s symptoms had started to show – but Dante states, as he’s helping the civilians, that Vanitas had already known that. Admitting this, Vanitas points out that Amelia had been so cold that she could hardly stand, black tears fell from her eyes and chest and with the shadowed thorns it meant that Amelia’s ill omen name was Eglantine. Confused, a shaky Noé questions what Vanitas means by an “ill omen name”, with Vanitas explaining that because of her disease Amelia received an ill omen name, which acts as the shadow of her distorted true name. It had been because of this distortion of her true name that Amelia lost her very self, and thus was succumbed to her thirst for blood more easily. Dante urges him to just carry on with curing Amelia already – for which Vanitas calls him an impatient baldy; much to his chagrin, as he’s not bald. Concerned, Noé asks if Vanitas intends to kill Amelia, and whether or not he’s a Chasseur from the church or one of The Bourreau sent to dispose of her. This makes Vanitas laugh, denying that he is either, Vanitas takes out The Book of Vanitas and claims that he is a doctor and that Vampires are his specialty; surprising Noé.
Vanitas proceeds to open The Book of Vanitas, which shines forth a bright light as Vanitas suggests that they return Amelia’s true name to her. As Amelia is engulfed in the light her shadowed thorns disintegrate, and the light touches her soul – where she is shown to be encased in a forest of thorns. Recognizing the warmth as spring sunlight, Amelia follows it to the edge of the thorns, where Vanitas corrects her by saying that the warmth was hers and hers alone, reaching through the darkness and pulling Amelia back into the warm field where flowers dance through the air.
Outside her consciousness, Vanitas speaks Amelia’s true name: Florifel, she who guides spring – believing it to be very fitting for Amelia. Amelia, shown to have regained complete control of herself is crying as she’s shocked to hear her true name, subsequently thanking Vanitas for returning it to her. Amelia then slumps in Vanitas’ arms – prompting Dante to ask if she’d died – but Vanitas assures both Dante and Noé that Amelia is simply unconscious.
Suddenly, two officers make their presences known as they approach from behind and aim their guns at Vanitas and Dante. Looking around, they see the damage Amelia had done and question what had happened there and ask if they aren’t the two trespassers that had crashed through the observation room. Vanitas admits this much and stands, advising the officers that they don’t want to have anything to do with them, or else they are going to get hurt. Unexpectedly, a piece of debris falls from the ceiling and hits Vanitas on the head – catching him off balance so that he falls back and out of La Baleine through a hole in the wall. Noé rushes to catch Vanitas, grabbing his ankle as the two of them plummet into the streets of Paris.
Having survived the fall, Vanitas and Noé walk through the streets of Paris, where Vanitas persistently asks Noé to lend him his strength; only to be repeatedly shot down. Vanitas argues that Noé couldn't possibly have a reason why they couldn't join forces, as Noé's yet to listen to what he has to say yet - suggesting that if Noé were to talk it out with him he'd better understand the situation; while also questioning where Noé was going and announcing that he's hungry. Noé simply tells Vanitas that he's quite annoying, admitting that his head feels heavy and that there's somewhere they must go first - which Vanitas accepts, suggesting that they run Noé's errand first and then talk afterwards.
Noé leads them back to The Baleine, prompting Vanitas' concern, where he states that he needs to retrieve Murr and his luggage. Soon after, Vanitas and Noé were spotted by the guards from The Baleine, who identify Vanitas as the intruder and proceed to take both of them into custody.