Synopsis: Mizuki & Caerula Arbor
| “ | The sea breeze blows past your shoulders to the other end of the ocean. There lies your destination, but you are yet to begin your journey. Pack your belongings and get ready, for the sea awaits your arrival. | ” |
Mizuki & Caerula Arbor focuses on the eponymous character and the Doctor's mission to conduct research on the Seaborn at the Iberian coastlines. Through a strange, ancient stele found along the coastlines that provides visions to the Doctor, it also expands the alternate timeline following Under Tides or Stultifera Navis in which Skadi succumbs into her Seaborn side due to the plot of the Church of the Deep, forcing the Doctor, Mizuki, and the surviving Operators of Rhodes Island to embark on a long journey of stopping the rampaging of the Seaborn and the revival of Ishar'mla, the "god" of the Seaborn, amidst the "second" Profound Silence that devastated the entire Terra.
The Waves Beckon
It all begins with a simple scientific investigation conducted by R.I.'s Iberian branch.
Following R.I.'s cooperation with the Abyssal Hunters and the Inquisition, R.I. is allowed to gain research access regarding the Seaborn; Tulip is in charge of the study and the Doctor arrives to assist her. However, they are accompanied with a special guest – Mizuki, an Aegir with Seaborn blood. He somehow hears the call of the ocean and tags along with the Doctor to find out more. Along the way, Mizuki recalls his memories with Cicero, the old man who adopted him. Even though he is in fact a bishop of the Church of the Deep, Mizuki meditates on what Cicero once said: "How do you become a better human?" Upon arriving at Cicero's old residence, Mizuki finds nobody inside and heads into the ocean to search for his whereabouts, asking the Doctor to accompany him.
Meanwhile, the coasts of Iberia is rocked by various ill tidings; the Church of the Deep is conducting an insidious plot in Sal Viento and Gran Faro has just been recently become their target. While Skadi, Gladiia, and Specter are bitterly resolving the matter with the Church, a single mistake will lead into a totally different outcome that could be apocalyptic to the surface.
On the R.I. side, the investigation team has unveiled a mysterious stele among the ruins along the coasts. After Mizuki wards off the Nethersea Brand that corrodes the stele, it suddenly glows abnormally. Realizing its importance, the Doctor has it recovered for further research.
From this point, multiple lines of future stem out, and the Doctor is able to gain access to read the vision broadcasted by the stele.
Exist or Extinct?
Of the four endings, Precious Days is canon to the Arknights storyline while the rest are non-canon due to taking place in alternate timelines. Nevertheless, these alternative timelines are broadcast to the Doctor from the ancient stele found in the canon timeline through Mizuki's Seaborn telepathy sense, and such future could be avoided if they make a right move.
Precious Days
At the depths of the grove, Mizuki encountered both Cicero and Highmore. The Iberian Islander has yearned to become a member of the Many, and she strongly urges Cicero to offer her Seaborn flesh despite the bishop's unwillingness. However, she is overwhelmed by the hivemind and starts to regret, and this leads to the side-effect where she transforms into a majestic Seaborn, forcing Mizuki to fight her.
Upon her defeat, Highmore reverts into her human form and fell unconscious as Cicero reveals himself. The bishop then talks with Mizuki regarding the difference between them; specifically, while Mizuki came to terms with his human consciousness, Highmore sought to embrace the Seaborn, but was unable to accept both her humanity nor the call of We Many. As Mizuki criticizes Cicero's ideas of a perfected humanity for rejecting those without enough fortitude, Cicero admits his mistake and notes that Mizuki's actions had answered the question he asked the boy long ago: "How do you become a better human?" As Mizuki and Cicero parted ways, the boy decides to spare Highmore's life.
After Highmore regains her consciousness, Mizuki cooked her detached limbs for them to eat, which she is initially uneasy with. Realizing her failure to be one with the Many and being reassured by Mizuki that they just need to live the way they want, Highmore agrees to tag along with him, and all's well that ends well.
Endbook: Crossroads
Ulpianus raided Cicero's lab and found a set of disclosed files there. These files recorded many notable names of Academies of Technology, Academies of Science and the art world of Aegir with most of them being in the Church of the Deep's control, and the plan to entice Skadi, the Huntress who defeated Ishar'mla, and "awaken" Him.
Although his investigation was immediately interrupted by the rushing Seaborn, Ulpianus knows what he must do—to prevent the surviving Hunters from returning to their hometown.
Endbook: To Usurp Divinity
The story is from the perspective of Cicero who analysed the nature of the Seaborn. He observed that every creature has the instinct of growth, survival, reproduction and migration, but Seaborn is the perfect one for all of them. As a former researcher, he is amazed by such nature and wished to achieve in building up a same mind across all living beings. He claims the existence of "Gods" - not the Seaborn themselves, but whatever grand force gave rise to such perfect beings in the first place. If they are the "Gods", he resolves to be the "thief", stealing the "olive branch" from the realm of divinity to let humanity transcend into a higher form.
Endbook: The Sound of Withering
The story sets in an alternative timeline where Mizuki failed to save Highmore after her transformation into the Paranoia Illusion. She greedily ingested Seaborn flesh to fulfill her long-waiting desire of rejecting her own humanity. However, as a result of her failure to become one with the Seaborn's hivemind nor retain her humanity, she ended up transforming into a being that is neither a human nor a Seaborn. After a painful struggle, she was implied to have lost her mind completely, disappointing Cicero who had been hesitant to let her transform herself for this reason. In the end, the old bishop quietly left while leaving her behind to suffer a slow death.
Age of the Silence
In this timeline, Mizuki encounters a tide-hunting knight who picked up the ocean's scent from him and decides to accompany him, believing that he wants to "slay the ocean" as he does. At one point during their trek, the tide-hunting knight encountered a ferocious storm described as the full might of the sea and sky combined, which he repelled either with Mizuki's help or single-handedly; in the latter case, the knight's armor is damaged in the process.
However, the tide-hunting knight eventually mistakes Mizuki for the root of the calamity, and decides to abandon his entourage right before he ventures into the inner groves, only to reveal himself as the legendary Last Knight from Kazimierz deep in the grove and face the boy in combat. The Last Knight proves to be a formidable foe to the point where Mizuki and co. barely scratches him unless if his armor is damaged beforehand.
The Last Knight manages to overpower Mizuki, but at this very moment he realizes that Mizuki is not the true threat, and that an ominous presence is near. That presence turns out to be Ishar'mla Himself, now awakened from His slumber and bringing the full might of the Many behind Him, poised to unleash the second Profound Silence onto the entire Terra.
Ishar'mla's presence is enough to give pause to The Last Knight and Rocinante due to their Seaborn blood, but knowing that the embodiment of the very ocean he wish to slay is right before him, the ecstatic knight and mount pair ready themselves for a final charge against the Firstborn. Regardless, Terra's days are numbered, and sooner or later, all will fall into an eternal Silence under the waves.
Endbook: Final Bastion
Every country on Terra finally unite as one by putting aside their past conflicts and tried hard to defeat the Seaborn amidst the devastating tsunami, but it is just in vain. The Abyssal Hunters and Inquisitors, including Carmen himself, are annihilated by the sea monsters, and Aegir is forever drowned in the deep abyss. The knights of Kazimierz and Gesatzswächters of Leithanien succumb within a single day, and the Seaborn quickly evolve to easily destroy both the ancient witchcrafts of Sami shamans and even cutting-edge Columbian technologies. As a last resort, the Ursine Emperor's Blades commit suicide to create tough barriers born from the Icefield Collapsals, yet the Seaborn evolve fast enough to eventually penetrate these psychic walls. In the end, the last Tianshi of Yan sacrifices himself in this apocalypse to buy time for the remaining humans to flee.
In the darkest hours, Kal'tsit humbles herself to the Feranmuts and seeks aid from the Lords of the Beast to retrieve ancient technologies left forgotten by the previous civilization that once colonized the Terran planet. They achieve to build the "Last City" — humanity's last resort — under Rhodes Island's supervision. Even then, its limited capacity forces her to shut the door for the others outside and leave them to die once the city was full, something that weighs on both her and Amiya's consciences. Nevertheless, the Last City is under the eyes of Ishar'mla who yearns to assimilate the Doctor while hiding under the flooded ruins of the Iberian royal court.
The Last City will also lead to two possible futures:
- The Seaborn will eventually spare the survivors of humanity and set sail to distance planets in outer space. However, by that time, all the familiar figures of R.I. except Kal'tsit are almost gone, and old Jordi, who has witnessed all the tragedies and now departure from there, passed away on his deathbed while witnessing their departure. The few surviving humans move on to rebuild civilizations bitterly and sorrowfully.[1]
- As the "Primordial Lifespring" — the plankton-like Firstborn responsible for the Profound Silence — completely goes berserk, even the Last City could not withstand its impact. Out of starvation, humans are forced to consume Seaborn, ultimately assimilating them into the Many. In the end, Terra is forever the planet of the Seaborn.[2]
Endbook: Resistance
The Last Knight dies under Ishar'mla's wrath, and Mizuki tries his best to send the Doctor back safely. Ishar'mla's mind orders Mizuki to bring them to Him, but he refuses. In the end, he is ultimately killed by the Many, and his body is violently devoured by the waves.
Endbook: Ashes to Ashes
As Mizuki's consciousness slowly diminishes in the abyss, his soul witnesses the decaying body of the Caerula Arbor, the Firstborn of the "Creeping Branch." Only one cell from his body is implanted onto the corpse of the Arbor. Nevertheless, there seemea to be a new hope as the Arbor appeared to grow new leaves after assimilating Mizuki's remains.
Price of Peace
In this timeline, as Terra is on the verge of being overwhelmed by the Seaborn and the Abyssal Hunters used the Stultifera Navis to return to Aegir, Mizuki and the Doctor decide to head into the deep ocean in order to set things right, taking Cicero's research notes with them due to the vital information it provides.
Mizuki and co. encountered an ancient laboratory acting as a fountainhead of the Seaborn. Deep within the laboratory, they encountered what's left of Caerula Arbor, one of the Firstborn Leviathans who had lost to the other Firstborn over the control of We Many. Noticing Mizuki's presence, the Arbor urges him to stop Ishar'mla and passes on all the power He can spare to the boy.
As they head deeper, Mizuki and co. finds out that the Hunters have fallen into a trap laid by the Church of the Deep as part of their plan to awaken Ishar'mla, and all of them but Skadi have perished. Upon reaching Ishar'mla's inner sanctum, it is revealed that Skadi now had become one with the Firstborn. With the fate of all Terra at stake, Mizuki engages Skadi/Ishar'mla in one final battle to decide everything.
Thanks to the power bestowed by the Caerula Arbor, Mizuki manages to defeat Ishar'mla and deals a blow from which the Firstborn would never recover. Despite Mizuki's victory, the Church's interference means that there is still one loose end to tie up: the rampaging "Primordial Lifespring" is on the verge of unleashing a calamity grander than the Profound Silence, and someone must assimilate themselves with It to pacify the Many. Keeping his promise to the Doctor, Mizuki decides to do the deed himself, walking towards the ocean as the waters turn blood-red. By the time the ocean returns to normal, Mizuki has disappeared.
The Seaborn menace is finally over as peace returns to Terra for now... but all this came with a great price. Mizuki will never return to the land again, and Rhodes Island has forever lost one of their prominent members.
Endbook: Farewell
After Mizuki's sacrifice that markes the end of the Seaborn threat, Terra returns to the ordinary days of endless suffering across the land. Even Aegir continues its eternal isolationism out of its pride. Nevertheless, Rhodes Island continues their activities to both focusing on its original goal in healing Oripathy and resolving greater otherworldly threats of Terra.
However, not everyone is glad for this happy ending. Every year, the Doctor will stop working for a day, go to the Iberian seaside, and stay there alone until the sunrise next day. They wish their presence and words would evoke Mizuki's consciousness in the vast ocean, but the dust has already settled. Nevertheless, the ocean forever remembers the Doctor by gladly having the waves beating their feet with luminous "blue tears."
Endbook: Recollection
Ishar-mla fails in His struggle against the Arbor and lost His position as a Firstborn. As a result, He is forever cast off from the Many and enters an eternal slumber. With His power diminished, He releases His control over Skadi. Although she initially cannot remember what happened, she gradually remembers her grave sin and laments. She finds the Doctor and seeks to reunite with them, but the cruel memories break her heart.
Endbook: Lamentation
Skadi is now an outcast of both humans and the Seaborn. Memories of her past flood her mind, but she could only respond in sorrow, unable to return to the land or face the Doctor out of shame. Out of grief, she hides herself inside an underwater ruin and keeps on singing out of instinct, her song broken despite knowing it by heart. Sadly, no one can hear her anymore as the waves forever silence her voices.
Stella Caerula
| This ending is added on Mizuki & Caerula Arbor's Expansion II. |
Branching off from the timeline that would lead into the Price of Peace ending, Mizuki and the Doctor heads out into a location pointed out by a map found among Cicero's research notes and had to take a harrowing memento of the Firstborn with them, which leads all the way to where the Caerula Arbor's remains was found. Mizuki thought of an idea to set things right: if he could remade himself into a new Firstborn, by assimilating with the Arbor's remains, he would be able to use its power to figure out a better solution to end the Seaborn menace. The Doctor goes along with the idea and resolves to see through the entire process.
Upon reaching the hub where the Arbor is being experimented upon and Mizuki starts his "ascension", the Doctor can either choose to interrupt the process out of his safety or let it continue which would have the Arbor lend some of His power to light the way forward. As the "ascension" is entering its final stages, Mizuki's individuality is tested; will he remains the Mizuki everyone know or change into a something else entirely? Depending on how lit the path he and the Doctor had traveled thus far, Mizuki could be determined to complete his goal, choose to bade his time, or choose to challenge the Many.
Regardless, Mizuki becomes one with the Arbor and the latter is now reborn as Izumik, the last of the Firstborn and the Source of Ecology, and the one who would decide Terra's salvation or destruction through one final test for the Doctor.
In the end, the Doctor managed to prove that Terra is worth saving and Mizuki's wish triumphed. Satisfied by the resolution, Izumik brings Mizuki back in a new body more-or-less identical to his previous Aegir form and thanked the boy for all they have went through, hence giving Him a new perspective in leading the Many. After Mizuki said his goodbye to Izumik, the latter calls out to all Seaborn in every corner of Terra's ocean and together with them, heads out into the space to carve out a new home for the Many somewhere among the vast sea of stars beyond Terra, clearly as the ending's name suggests which literally means "azure stars" in Latin, with Mizuki watching the wondrous spectacle.
As the saying goes, "The storm will eventually pass", the Seaborn menace finally resolves itself and Terra will surely return to what it was.
| “ | O Mother, we have found our answer. We many are of the sea, and to the sea we shall return. To the bright, boundless galaxy. To the new place we call home. | ” |
Endbook: Terra Reborn
The departure of the Seaborn leaves a wonderful gift to Terra. With their terraforming function restored, not only did the forests repopulate much of the land at a surprising speed, but the Seaborn even performs a miracle — removing Originium, the curse of Terra, from the planet entirely. Along with their departure, the Feranmuts, the ancient natives of Terra, rise from Their "hibernation" and explored Their newly reformed homeland.
As Mizuki looks around this new paradise, he heads towards the site of the Last City. However, he is unable to find it, as Terra has changed significantly during the millennia of his absence. Instead, he decides to leave fires and messages in every language he could remember, before climbing a mountain and waiting for someone to answer his call.
Eventually, a Liberi woman finds him and threatens him at knifepoint, while speaking in a language resembling an amalgam of many preexisting ones. Upon seeing her Rhodes Island badge, Mizuki remembers his past.
Endbook: Rhodes Island
The Last City, once a refuge from the great flood, is the seed of a new civilization. During the apocalypse, mankind put aside their disagreement and dismantled their social hierarchy just to band together for survival. Now, there are no longer kings or nobles, and everyone is treated the same regardless of their status. This, of course, is all thanks to Rhodes Island's effort for generations, causing them to become a figure of leadership. With the Seaborn threat out of the picture, the Last City becomes free to expand outwards again, exploring the new world and rebuilding civilization.
Arriving at the Last City, Mizuki is uncertain about reuniting with Rhodes Island, as everything has changed immensely since his departure. However, once he enters the building, Kal'tsit is there waiting for a reunion.
Endbook: Continuation of Fate
Through Kal'tsit's words, Mizuki learns the current situation. The Doctor's plan and Mizuki's terraforming allowed the Last City to withstand the apocalypse and rebuild civilization anew, albeit with inconceivable sacrifices. Much to his surprise, the Doctor is still alive, with their life being prolonged using the Sarcophagus, which they are currently resting in.
Nevertheless, Kal'tsit seems to hide secrets from him for his sake. Despite the Sarcophagus' miraculous ability, unfortunately, age has slowly weathered the Doctor's body; even such a miraculous machine of the predecessors could not prevent their eventual death. Meanwhile, it turns out the Seaborn are actually artificial biological planetary terra-reformation devices created by the predecessors that somehow went out of control. Dismissing her troubled thoughts, Kal'tsit brings Mizuki back to his "home" — Rhodes Island, where he intends to resume his status as an Operator and work together to guide the newly reborn civilization since then.
Many years later, perhaps more than decades, as mankind's cities reach the seas once again, there is a little girl who shows her kindness to a surviving Seaborn by offering it food. It is from this moment that the Many learnt a new message, whether in the sea or up in space:
| “ | Humanity today is no longer a threat. We can coexist with humans. | ” |