Parallel worlds hold infinite possibilities. Different choices made in the same event can give birth to an entirely new parallel world. For example, the Einzbern family's illegal summoning during the Third Holy Grail War, or Dr. Heartless's investigation results.
If the investigation concluded that the Holy Grail in the Holy Grail War was truly a wish-granting device, Marisbury would have gone to Fuyuki City like Kayneth to participate in the Holy Grail War.
The relic he would have used was one of the ten rings that Solomon, the King of Magecraft of Israel, received from God—a key figure in the decline of mystery.
The combination of the Department of Astromancy, Marisbury, and the famous King of Magecraft would have secured a decisive victory in the Holy Grail War. The wish they would have made before the Holy Grail would lead to the creation of Chaldea, ultimately igniting the fuse of the Human Order Incineration. This would be the beginning of what we know as Fate/Grand Order.
On the other hand, if the investigation result was that the Holy Grail was incomplete and not a true wish-granting device, Marisbury would have abandoned the idea of participating in the war, Chaldea would never have been established, and the final fuse would have been snuffed out in 2015 with his suicide, preventing the Human Order Incineration from ever occurring. This is the worldline Shinji now finds himself in and the last move Trisha left behind.
Because of the detailed investigation, Olga Marie and Trisha were so familiar with the Holy Grail War, stringing together all the events that were shrouded in mist.
While the investigation result disappointed Marisbury, Dr. Heartless himself found something intriguing during the investigation: the beginning of the ritual known as the Holy Grail War—Servant Summoning, the great achievement of manifesting legends and myths in the modern era.
This was Dr. Heartless's true objective. To achieve it, he stole Iskandar's relic and forced Waver to board the Mystic Eye Collection Train.
The Mystic Eye Collection Train served as a link—a connection between the ley lines and the Greater Grail in the Far East.
Waver and Iskandar's relics were the guarantees, fooling the Greater Grail into thinking it was activating the Servant Summoning ritual by using the identity of a past participant of the Holy Grail War.
The moment the Servant Summoning was completed, his goal was achieved. Auctioning the Mystic Eyes Transcience or disguising himself as Caules to observe his successor up close was just for fun.
Now, with his interest waned, Dr. Heartless no longer intended to continue. He gently placed Trisha's head by his feet and raised his right hand straight.
On the back of his hand was a strange red pattern, containing extraordinary mystery.
"Miss Adashino! Dispel the barrier—"
Seeing this pattern, Waver shouted in haste.
However, Dr. Heartless's summoning was even quicker.
"By Command Spell, I order you! Come forth—"
The barrier of light set by Adashino instantly dissolved in the face of an even stronger light.
In the center of the light, next to Dr. Heartless, appeared a woman.
A true warrior could only be described as someone like her.
She appeared to be in her early twenties, tall and imposing. It wasn't just her height—her natural posture, even when surrounded by enemies, made her seem even more formidable.
Simple leather and metal armor wrapped around her slender body, with a straight sword at her waist that seemed just right for her. The well-tanned leather gauntlets didn't hinder her fingers' movement in the slightest.
Her slightly wavy, mid-length hair had a single braid hanging down to her ankles. One of her eyes was as blue as the sea, while the other was as black as a raven's feather.
"..."
"..."
"A Servant..."
"To think he summoned a Ghostliner..."
Olga Marie stumbled, Luvia trembled, Adashino's calm façade was shattered for the first time, and even Lorelei wavered in the face of this woman's presence.
Because of their families or affiliations, they all knew about the existence of Servants and had heard of their extraordinary strength, but hearing was different from witnessing. Many things and people can only be truly understood through personal experience.
Her presence was unparalleled.
It was a pressure comparable to the Twenty-Seven Dead Apostle Ancestors.
It was a manifestation of mystery far beyond anything they had ever encountered.
Even the Queen of the Clock Tower, the pinnacle of modern magi, had to be fully alert to face this formidable opponent!
The female warrior who appeared out of nowhere leisurely turned her head to Dr. Heartless.
"I'm getting impatient, Master."
"Haha, my successor's words were so interesting that I lost track of time."
"Boring."
The female warrior scoffed at him.
Gray tightened her grip on Add, her legs trembling uncontrollably, while Rodin, Leandra, and the acting manager all wore grave expressions as if facing a deadly foe.
This wasn't the first time they had encountered this female warrior. On the evening of the second day after Waver boarded the train, they had fought her once and were well aware of her strength. Even if the four of them worked together, Waver still ended up injured. Despite being the weakest among them, he was performing better than all the strong ones. He looked at the female warrior's face and spoke calmly.
"I've been wondering who you are, Servant."
"I told you, I am Hephaestion," the female warrior replied impatiently.
At that moment, a loud, exaggerated gasp.
"Huh? Did you say your name is Hephaestion?"
It was Shinji, who had somehow moved to Waver's side.
"Is there something wrong?"
The female warrior's voice grew colder, and the chilling gaze from her heterochromatic eyes was enough to freeze one's soul. In the West, such rare eyes were called Heterochromia.
Shinji's expression remained unchanged, unaffected by the warrior's intimidating presence.
"No; but, he's a man."
Who was Hephaestion? He was a famous warrior, commander, diplomat, and, above all, Iskandar's closest confidant and dearest friend.
Iskandar always led the charge, leaving Hephaestion to command the army in his place. Whenever Iskandar had to make a significant decision, he would consult Hephaestion to avoid mistakes. There are even legends that Hephaestion could share royal authority with the king.
One legend tells of Iskandar entering the palace with his close friend after conquering Persia. Darius III's mother, unable to discern who the king was, knelt before Hephaestion. Under the royal standards of the time, such an action would typically lead to execution, but Iskandar merely laughed it off, saying, "He is also Iskandar."
Their overly close relationship has sparked endless speculation throughout history, with many even considering Hephaestion to be Iskandar's male lover.
"Are you really Hephaestion?"
Sensing amusement in his words, the female warrior's eyes locked fiercely onto Shinji.
"Die!"
With those words, the woman stepped forward.
With astonishing speed, she closed the distance and drew her sword!
Shinji still had no intention of wiping the smile from his face and slowly raised his left hand.
However, someone moved even faster than her. Accompanied by a whistling wind, a dark shadow intercepted the path of the sword.
A loud "clang!" echoed as metal collided.
A black whip blocked the woman's sword—Lorelei had made her move. Her reason for doing so was simple.
"No one can act so arrogantly in front of Barthomeloi!"
Barthomeloi represents the law and governance of the Clock Tower. No magus can act recklessly in front of them, not even a Servant!