The two fought their way from the thirty-second floor down to the first-floor lobby.
Then they charged out onto the street outside the hotel's main entrance.
Shock waves from the clashes between Excalibur and the twin demonic swords gouged cracks into the pavement along the entire street.
Seven or eight streetlights toppled. Two cars parked by the roadside were first overturned, then trampled out of shape.
Water from a severed fire hydrant shot diagonally into the air. As the night wind blew, icy mist filled the surroundings.
Out on the street, Diarmuid barely managed to keep up with Artoria's pace.
Against a holy sword wielded one-handed, the twin demonic swords did allow much faster transitions between offense and defense.
The longsword handled frontal blocks and counters, while the shortsword redirected force and delivered follow-up strikes. Working together, the two blades could link defense and retaliation within the briefest opening.
That kept Diarmuid from being overwhelmed outright by Artoria.
But that was all it did.
Artoria's mana output with every swing was now above A-rank.
Every time Diarmuid blocked, his arms bore tremendous pressure. Given enough time, his body would give out first.
Inside the Hyatt Hotel, in the surviving section above the twenty-fifth floor.
Kayneth stood amid the ruins of his Magecraft workshop.
Although that last strike had pierced the outer bounded field and vaporized five floors, the truly important defenses were not outside, but on the three Mana Furnaces.
Each of those three cores, made from the remains of the Age of Gods dragon Albion, had its own, stronger Magecraft shield wrapped around it.
The outer bounded field had shattered, but the cores remained.
All three Mana Furnaces were undamaged and continued to supply mana.
Kayneth stood in the triangular space enclosed by the three cores, with Volumen Hydrargyrum circling him on standby.
Over a hundred kilograms of specially formulated mercury hovered within three meters of his body, forming a flowing silver defensive line.
Standing here, within the three cores' supply range and with Volumen Hydrargyrum's all-around protection, Kayneth was the Master with the strongest one-on-one fighting ability in this Holy Grail War.
Kayneth understood his own role very clearly.
He was not the sort of Lord who relied purely on martial strength.
If Lorelei Barthomeloi of the Clock Tower were brought onto the field, even ten Kiritsugu Emiyas together would not be a match for her.
Someone like her was a weapon of war in her own right. Comparing himself to her would only invite frustration.
But Kayneth was not someone who relied on talk, either.
What he excelled at now was defending his workshop.
He had the terrain advantage, three cores supplying mana, and Volumen Hydrargyrum automatically detecting enemies and defending him.
Anyone who charged in head-on would only be dragged into a war of attrition that would be very difficult to escape.
The only thing he needed to watch out for was Kiritsugu Emiya's Origin Bullet.
Kayneth had already read about Kiritsugu Emiya's methods in the intelligence he had brought from the Clock Tower.
What that man used was not proper Magecraft, but conceptual magic bullets created from his own Origin of Severing and Binding.
As long as the target still had Magecraft or mana defenses active when the bullet struck, the Origin's effect would strike directly into their Magic Circuits, severing them before chaotically reassembling them.
For a mage, that sort of damage was troublesome, essentially leaving them crippled.
If he really fell victim to that, Kayneth would lose his position in the Clock Tower as well.
So Kayneth simply settled on a rigid strategy.
He would not leave the workshop.
He would let Lancer keep Saber occupied outside while he guarded the workshop's core, with Volumen Hydrargyrum on full standby.
As long as he stayed out of Kiritsugu Emiya's line of fire, the Origin Bullet would have no chance to hit him.
Kayneth waited for Kiritsugu Emiya to attack.
Come, then. Inside my workshop, no Master can defeat me.
Three minutes passed.
Kiritsugu Emiya did not appear.
Five minutes passed.
Still nothing.
The sounds of Artoria and Diarmuid fighting in the street traveled up through dozens of floors.
The dull tremors kept shaking debris loose from the surviving ceiling.
Apart from that, Kayneth's workshop area was oppressively quiet.
Then Kayneth heard a noise.
It came neither from above nor from outside.
It came from below.
Far below.
Boom-
A muffled explosion sounded deep in the Hyatt Hotel's foundations.
Explosives.
Kiritsugu Emiya had blown up the support columns on the Hyatt Hotel's lowest floor.
Not just one, either, but every load-bearing column.
With its support at ground level gone, the thirty-two-story reinforced concrete building began to collapse in its entirety.
The weight of the upper stories pressed down through the floors. Each floor slab, unable to withstand the weight above, shattered, fell, and smashed into the next floor.
The chain reaction rapidly spread downward.
Kayneth's face had gone pale the moment that low-frequency tremor reached his ears.
He immediately understood Kiritsugu Emiya's plan.
That man had never intended to storm the workshop head-on.
Evacuating the civilians and having Saber charge in from the front had all been cover.
His real tactic was the simplest, crudest method, and the one that required the least Magecraft.
Blow up the building's foundations and turn the entire structure, along with the Magecraft workshop inside, into rubble.
Kayneth had no time to think any further.
The floor beneath his feet began to fracture.
Volumen Hydrargyrum reshaped itself within a tenth of a second, abandoning control over the surrounding space and concentrating all its power around Kayneth. It compressed into an extremely dense silver sphere, enveloping him completely.
At the same time, Kayneth tried to extend the mercury outward to reach the three Mana Furnaces.
There was not enough time.
He only managed to reach two.
Mercury tendrils wrapped around the two Mana Furnaces nearest him and dragged them inside the defensive sphere.
The third was the one placed in the workshop's eastern corner.
The instant the floor shattered, it lost its support and fell into the collapsing ruins, independent shield and all.
Tens of thousands of tons of reinforced concrete crashed down from thirty-two stories high, reducing the Hyatt Hotel's former site to an enormous mound of rubble.
The rising dust obscured everything for hundreds of meters around. The sounds of falling glass and concrete continued for a long time before slowly subsiding.
Deep within the rubble, the silver sphere of Volumen Hydrargyrum held against hundreds upon thousands of tons of pressure from above.
Kayneth huddled inside the protective mercury shell, with two Mana Furnaces pressed close beside him.
He was still alive.
But the third Mana Furnace was buried at some unknown depth.
The furnace itself was probably undamaged. Something made from Albion's remains would not be crushed so easily.
But digging it out would still take time.
Kayneth gritted his teeth in the darkness.
Three had become two. His mana output had dropped by a full third.
The metallic clashes coming from the distant streets grew increasingly frequent.
The battle between Excalibur and the twin demonic swords had moved from near the Hyatt Hotel's ruins to three streets away.
The pavement, streetlights, fire hydrants, and cars parked along the route were all caught up in it.
Fragments and sparks scattered through the night.
Diarmuid was already starting to falter.
The combination of twin demonic swords could hold off the King of Knights for a short time, but holding her off did not mean he could keep fighting her to a standstill.
The mana Artoria poured into every swing remained firmly above A-rank. With every blow Diarmuid caught, the strain on his arms increased a little more.
The red longsword, Surging Waves of Fury, had begun to emit a faint tremulous ringing.
It was not that the sword was about to shatter, but that its wielder's wrist was beginning to give out under the prolonged, intense blocking.
The yellow shortsword, Ripples of Passion, could still help shed some of the pressure, but that slight relief could not keep pace with the accumulating damage.
Time was on Artoria's side.
The ruins of the Hyatt Hotel.
Tens of thousands of tons of wreckage formed a small mountain.
Rebar twisted out of chunks of concrete, and the dust had yet to settle completely.
A light suddenly flashed midway through the rubble.
Silver light shone from within, flowing like metal.
A silver sphere emerged through a gap in the ruins.
The sphere was roughly two meters across, its surface shifting like liquid mercury.
As it squeezed through the rebar and concrete, its shape changed to fit the gaps, flattening, stretching, then slowly returning to a sphere. The entire process was utterly silent.
After leaving the rubble, the sphere hovered roughly a meter above the ground.
Then it split open.
Its silver surface parted to either side like liquid, revealing the person standing inside.