Originally, when Shiomi set this war in motion, he had already prepared everything.
He would lead the Londinium army toward Camelot, drawing the attention of all Britannia. Meanwhile, Baobhan Sith would take Artoria Caster, carrying his Gáe Bolg as proof of identity, and head southwest to the Storm Border beyond the Mist Coast to seek Chaldea's protection.
In this Britannia, which had transformed from a Lostbelt into an Anomaly World, everything living here now had the qualification to leave without being erased by the universe the moment they stepped outside. Baobhan Sith and Caster were no exception.
Because Shiomi had no way of knowing how far the war would spread after he collapsed, or how much unpredictable loss it might bring, sending Baobhan Sith and Caster to take refuge under Chaldea's protection was the only thing that could give him peace of mind.
He believed that during this period, Morgan would be far too busy to pay attention to anything else.
Yet when Baobhan Sith and Caster secretly made their way toward the Mist Coast, they ran into a man calling himself Grímr on the southern plains.
Or rather, he had been waiting for them on the only road they could take.
After using Caster's Fairy Eyes to confirm Grímr's identity, Baobhan Sith—who knew the deeds of the previous Grímr—answered truthfully when he questioned her about Shiomi's condition.
She even told him about the act of sealing the calamity at the cost of his soul.
Shiomi had concealed nothing from Baobhan Sith. He believed that only by understanding everything clearly could she make the right decisions.
She had been raised at her father's side for two thousand years and understood his intent deeply. Even if it hurt, she would still carry out what Shiomi entrusted to her.
But after hearing her explanation, Grímr said there was still a way to save Shiomi, and he intended to head for Camelot.
At that point, Baobhan Sith changed her route. She and Caster followed Grímr back, and with her status as a princess, she helped him pass through the Londinium army's strict checkpoints without trouble.
"Grímr…?" Morgan had no interest in exchanging greetings with an old companion from the Pilgrimage era, especially when he now appeared in the form of a young man and she herself remembered nothing of those millennia. "You said you can save my husband. What do you mean by that?"
Everyone's eyes fell on Cú Chulainn.
To Morgan and Habetrot, Grímr was a comrade from the past returning to Britannia.
To Chaldea, he was the Caster who had assisted them in the Fuyuki Singularity.
And with someone like Scáthach present, who had a direct connection, no one needed to question whether he was genuine.
"The Great Seal. Using one's soul as the price to seal a calamity." Grímr pointed at Shiomi. "Honestly, the seal itself isn't complicated. With a bit of time, it can be undone. But that's not the issue."
He spoke while turning toward Ritsuka, though the real target of his words was Chaldea's communicator.
"Chaldea—Romani. Can you analyze my junior's condition from your side? If you can, I can explain." Grímr rested on his staff. "All of this is information the great god Odin shoved at me. It's not something I knew on my own."
Romani immediately used the Storm Border's systems through Ritsuka's communicator to perform a spiritron scan and analysis of Shiomi. Just like back in Uruk, the results were projected before everyone through Mash's shield.
"The spirit particle readings show that Shiomi's soul is heavily clouded," Romani said. "This is… the result of an overload of Curse energy mixed into it."
"Exactly. If you recklessly undo the seal and force Cernunnos, the sealed Beast God, back out, the outcome is simple. Before this guy even wakes up, Cernunnos will turn around and devour him, using him as the core that keeps it alive." Grímr pinched his chin, his expression severe. "Don't forget—he possesses the Life Authority acknowledged by the goddess Tiamat."
No one could predict how far the Life Authority's bearer—embedded in the Beast God's remains, settled for ten thousand years, then drowned in a curse sealed for sixteen hundred—would be activated if the seal were undone.
"So you're saying we need to break the seal while simultaneously separating my disciple's soul from Cernunnos?" Scáthach immediately caught the key point and questioned Grímr. "Is that what you mean, Cú Chulainn?"
"I told you not to call me that, Master. It lowers my Spirit Origin output." Grímr protested with obvious irritation, then answered clearly. "But yes, that's correct."
Artoria asked, "Then as Odin's proxy, you possess the power to do this?"
"No." Grímr denied it without hesitation.
Everyone froze for a moment, confusion and even frustration showing on their faces.
"Don't look at me like that. Souls were never my specialty, and even as a proxy, the power I can use is extremely limited." Grímr remained calm. "Honestly, at this stage, you should all have a better idea than I do about how to extract his soul from the curse. Right, Romani Archaman?"
He finally turned the question to Romani. Though Romani had never revealed his true identity publicly, his extensive knowledge of Magecraft had left a strong impression on everyone.
"…The Third Magic, Heaven's Feel," Romani suddenly said. "If we could recreate the Third Magic here, then we should be able to—"
Hope lit up in Sakura's eyes.
"The Third Magic was the foundation of the Fuyuki Holy Grail War. Mother, who once participated in that Holy Grail War as a Servant, analyzed the system and purified the Greater Grail—she could definitely—"
She instinctively turned toward Morgan, who had been silently listening. But in the Queen of Winter's eyes, she saw only confusion.
"The Third Magic? What theory is that?"
"Eh?" Sakura froze.
Scáthach and Artoria also froze.
Only then did they fully realize.
The Morgan standing before them was not the "Morgan" they knew.
"Wait—did the documents we took during the retreat not contain any records of the Third Magic?" Scáthach asked.
"If they didn't…" Artoria also understood the issue.
If Morgan had truly analyzed the theory, she should have left behind relevant research for emergencies.
"That is what you must do next, Morgan," Grímr said calmly. "I know that in this Britannia, you used the throne to gather two thousand years of Mana. It's more than enough to substitute for the Mana the Third Magic requires, which is normally produced by converting Servant souls."
"My… task?" Morgan found a thread of hope in their discussion and forced herself to remain composed. "Tell me. What must I do to save my husband?"
"Go to the Fourth Holy Grail War. As a Servant, you'll gain access to the Greater Grail and analyze its underlying theory. I doubt it will be difficult for you."
Grímr's proclamation echoed through the council chamber like a divine decree.