Within the forlorn sky of mist, sunlight peeked out to pull us all out from our slumber and rest. I rubbed my eyes as I got up from the bed and saw Mordred sprawled about on her comfy cot.

Hungry enough for the morning, I decided to reach within my rucksack and rummage around for my convenience store snacks. To my grumpy dismay, they weren't even in the bag.

Until I found the whereabouts of it in this room's shared waste bin…

"Ah. So even when you're not in Chaldea, you're like this, eh?"

I walked over to the knight and looked her over with my sleep lidded eyes.

Her hair was a messy nest and a dopey smile belied her comfort in dream land. You'd certainly wonder what the hellcat knight would be dreaming so happily about, considering her lore and all. Thinking that I needed some activity to wake me up for today, I decided on my course of a morning routine.

"Mordred?"

No answer, save for more pleasant snoring.

"Momo ~?"

Out of some reflex, her face scrunched up in disgust yet stayed asleep.

"Eh, all good ~" I soon held my hand out above the sleeping knight, "Oh ye, nereids, give unto thee the boon of water..." Cool drops of dew dropped from my outstretched palm, which soon turned into a burst of water.

Gasping noises soon replaced the peaceful snoring of the roguish knight. "He-HEY! The hell'd you do that for, you fucking moron?! Could've just jolted me out of bed, ugh…"

"Well, well, that sure sounds like someone that didn't happen to raid my stash of snacks here…" I reached for our waste bin and found half of the bin filled up with a more than fair amount of my snacks. "Objections, oh, sir knight?"

"Grr, fine! We're even, we're even!" She rubbed her eyes and reached for a hand towel by her side to dry herself, "I sure hope you feed my other self well, shitty brat…"

"Your other self stuffs herself plenty on my snacks, mind you." I had my fair share of payback for this snack plundering knight for today.

For this Mordred, at least.

"Anyways, we have a big day today, Master." The knight spoke up after she had wiped up a majority of her soaked self free of conjured water, "That four-eyed shit actually had this one helluva lead going on: Some sorta place underground that's got some shady shit goin' on."

Underground, huh? That's certainly quite appropriate for the whole mysterious London thing going in here…

Soon enough, I dressed up for the day and met up with the rest of the team. Safe to say, we all seemed more at ease within this horror movie-esque Singularity; All of us seem to have rested enough and well, all decked in our respective gear.

Not a bad start to a new day, I suppose.

"Ah, there you are, Master. Did you sleep well?" Dantes asked me as he sat on one of the chairs.

"Hmm, slept as well as I could in a murder mystery setting, Dantes." I chuckled at my own response, "The homey interior of Jekyll's place here really does wonders for everybody's morale and sanity, y'know?"

The well-dressed Avenger gave me a slight grin and nodded at my response, "Glad to hear you're well enough to make light of our situation, Master, fufu." He then promptly stood up from his comfy spot, "Still, we should be getting ready to move out soon enough."

"Ah, are we that close now to cracking the mystery of this Singularity?"

"More or less, our findings seem to show that there's bound to be a lead in the underground of Londinium. Mana signatures have been noted to be much higher in concentration there, as per our efforts at reconnaissance." Fixing his hat, Dantes continued, "From a fair inference, I'd assume we'd be able to fix up this Singularity in due time, Master."

Well, the sooner we do get out of here, the better it is on all our ends.

That and I'd really love some of Emiya's cooking to ease my spirits.

"Looking alive, Chaldean." I scanned the room to look for the voice and found myself looking down upon the childish, blue mop of Hans, "I am going to assume you did that without meaning to, Chaldean. We've got to get a move on right now and I'm antsy to get back to the Throne at any moment."

I patted the fluffy blue hair of the childlike Caster, "Yeah, yeah, sure thing grumpy ~"

After a brief rundown of our plans for today, I headed out with my Servants in tow to find where the heart of the fog truly resided. This eventually involved a fairly reluctant venture down London's sewage system that a certain few of us were quite hesitant to walk around in.

By "certain few", I meant the Roman emperor straddling my shoulders as we walked around.

"N-nero, could you go down now by any chance?" I stammered as she rode upon my shoulders. "We've been at this for a good hour or so and my back is killing me right now."

"Nope! Not a chance! I refuse to soil my dress upon such filth, umu!" From where I was, I could definitely feel Nero childishly shaking her head and sticking her tongue out at me.

I tried to glance at my side and called out to Artoria, "Hey, Artoria, could Her Holy Roma hitch a ride upon your Dun Stallion?"

"Hm, I'm not sure if my steed would agree to taking up any other rider aside from me or you, Mas-"

"You'll have a plate of prime rib on me when we get back."

"... Consider it done then." With a snap, Artoria summoned her Dun Stallion and gently yet briskly picked up the emperor on my shoulders to mount her royal steed. Somehow, even as she matured to this great degree, food remains the best bargaining chip for the line of Pendragons.

"Woah! You all look like ants from here, Praetor!" Nero had a renewed sense of wonder and vigor as she rode upon the trusty steed, "Hehehe, I could definitely ride into battle like the liege I am from this angle, umu!"

I do suppose nobody would notice the pint-sized emperor in the battlefield without any stilts or steed…

"Praetor, I have a great feeling you just thought of something pretty insulting right about now."

I could only give a nonchalant shrug as a fairly appropriate response.

Oddly enough, the underground sewer complex of this city is remarkably quite spacious in its own right. Despite our fairly large group at the moment, the sewer's tunnels were still vastly spacious enough. The trace mana signatures upon the walls told a fairly large story of mage involvement in the city of Londinium.

It certainly begs the question of which mage institution was doing all their work under the plain sight of common people.

Our little trek in the sewers soon went into a halt, as Fran stopped in place. She looked around the place and grabbed her massive bludgeon.

On cue, the rest of my Servant retinue also decided to be on guard as we all readied ourselves for a chance encounter with more Helter Skelters and the like.

Mash stood in front of me with her massive shield in place, "Senpai, there is a significantly strong mana signature somewhere in our vicinity. Please be on guard."

J'Alter, Artoria,Nero, Mordred, and Jekyll all took out their various armaments at the ready as well.

"There is truly a foul taste in this air right now, Master" J'Alter said as she warily looked around, "Something big is coming our way this time around."

I materialized my handguns as a heavy cloud of fog soon enveloped the area and the ominous droning sound of clockwork in the vicinity. From the most concentrated point in the fog, two figures appeared out from it:

One figure was a man with blue hair. Dressed in a black coat, he reeked of something vile that I couldn't quite place in my mind.

The other figure was an imposing steel automaton that glared upon us with its single red eye. Steam was constantly being emitted around it as its mechanisms continued their clockwork humming.

"Ah, you must be the Chaldeans, I presume?" The blue haired man spoke as he looked upon us with a sneer of his own, "I can certainly see why the Grand Caster himself would appoint a number of us to put you dogs down."

I glared at him, "Apologies then, for being so persistent in ruining your whole setup here then. I don't quite like what's gonna happen in the future."

"It is pointless, magus. That is just as fate intended in its mechanisms." The machine spoke in response, "Surrender now or die under his wrath."

As those words left the machine, he materialized a steel bludgeon and enshrouded the entire area in fog and steam.

Shit, I can't even see them nor feel out their mana with this mana-dense fog around me…

In my peripheral view, I noticed a gleaming red eye-

The automaton was quickly stopped in place by Nero and J'Alter as they crossed their blade and lance with the heavy cudgel it carried.

"Hm, I suppose a single sneak attack was something in the realm of an Assassin rather than a Caster such as I…" With that, he vanished into the fog once more.

"This isn't good, it's difficult to pinpoint each of their whereabouts in this playing field…"

Dispersing all of this fog would certainly make matters better on our end. I looked at my party of Servants and a lightbulb popped into my mind as I saw Fran.

"Fran, unleash as much lightning as you can to disperse this fog away!"

With a brief nod, Fran channeled great amounts of lightning in her cudgel and smashed it on the ground in front of her.

For that moment, the fog soon dispersed into more manageable amounts and I was able to pinpoint the steel Caster.

"Dantes, Artoria! Blast 'em up at 3 o'clock!"

The two of them nodded and blasted beams of mana towards the right part of the tunnel. True enough, the azure and golden blasts were able to hit the Caster automaton hard enough to let down their guard.

"Artoria, let's give 'em chase!" I called out to the Lancer as she took my hand and brought me upon Dun Stallion, "We'll end this nice and easy…"

Reeling from the two-front attacks, the Caster got up and waved his bludgeon about, "Helter Skelters, arise! Arise, from my dreaded Dimension of Steam!" As he released his Noble Phantasm, the metallic automaton faded from view once more.

As a majority of the fog lifted, a swarm of Helter Skelters filled up the tunnel. Looking around, I noticed that they made sure to heavily block out any possible passageway for escape.

If they want to play rough, then they'll get it rough.

"Master! I'll hunt down the Caster, so please keep those Helter Skelters at bay!" Artoria said as she slashed and pierced at mechs that were in front of our way.

I nodded, "Alright, I'll keep you free enough to focus shots his way then." At this point, I had changed my armament to my own rifle as I blasted upon the horde of Helter Skelters. Glancing upon the other parts of this fog-filled tunnel, I could see that the rest of my Servants were handling themselves just fine.

At this pace, we were steadily milling the numbers yet there was no sign of the Caster nor the magus.

From an area within the fog, the Caster and mage argued about their odds of winning against Chaldea.

"Babbage, at this rate…" The blue haired magus brought out something from within his coat, "We just might have to resort to some rather extreme measures."

"Makiri Zolgen, you dare not-!?" The Caster mech glared at the mage in front of him as he saw the Holy Grail of Londinium brought out.

"O' Holy Grail, hear my wish and let this Caster wreak havoc upon all those affiliated with Chaldea!" With that, the mage's mad wish bore into fruition as the grail shined brightly.

"D-damn yoU, ZOLGEN!" were the Caster's final sane words as he increased in size and became a madness-blighted Servant.

"Deal with them, you steam-loving Caster. I have better things to do at the moment…" Zolgen said as he turned tail and hurriedly went to the other side of the tunnel on foot.

"I just have to get away from these meddling pieces of shit and summon a Servant to our cause via the Grail. Babbage should keep them at bay for long enough."

"S-senpai! There's a spike in mana-!" Mash frantically called to me from their position on the field. "Please be on guard!"

At that warning, Artoria and I saw an abnormally large Caster blocking our way to the other side of the tunnel. From what I could see past this vengeful wall of steel, I saw the blue haired mage from earlier sprinting towards the other end of the tunnel.

Shit, we can't let that mage get away!

Faster than I could see it coming, the massive bludgeon soon descended upon us, "Artoria! Look out!"

I closed my eyes and readied myself for the impact-

KLANG!

As I opened my eyes, I saw Fran blocking the massive Caster's armament with her own lightning-charged bludgeon. With gritted teeth and feet firmly planted upon the stone pavement, it was clear that this was taking a toll upon her.

"Fran!"

For a moment, the Berserker looked back at me and spoke in effortful words, "Ma-master...Go! Fr..fran and Hy...de stay!" The pinkette was soon assisted by a manic Hyde that soon joined the fray, "Yeah, Master! Leave this tin can to us!"

I felt a pit in my stomach at the possibility that this could be the last time we see them around this city of fog and cobblestone. As much as it is the most reasonable solution at the moment, such a decision is wracked with guilt…

"We'll see each other again, okay?"

The two Servants looked back at me one last time and gave me determined nods.

With that, our party rushed off in the further depths of the tunnel. The last scene behind us being two rampaging Servants against a massive steel automata of a Servant, was more than enough for a memento of the fights within this tunnel.

As we pressed our pursuit of the mage in this decrepit tunnel, a light soon came into view.

At the end of the tunnel's scenery, we were brought back to the air and streets of Londinium.

"Wait, a minute…"

The once dreary fog-heavy skies that once greeted us constantly had been replaced with a great lightshow of thunder and lightning above.

At the center of it all was none other than the Zolgen magus revelling in its chaos.

"What the hell is all of this…?"

Dismounting the hallowed stallion, I could only stare in fear at the sight in front of my Servants and I. "Singularity's all fucked up even more now…"

Artoria joined me on the cobblestone pavement soon enough, "Stay vigilant, Master. This is only the start of what is to come."

"You got that right." Mordred moved over to my side, "We've really got one helluva mess to clean up here, yeah?"

"We sure do have a shitshow for us to clean up here in London…"

My hands could only feel cold at how the skies of London were bright with blighted thunder and storms as malevolent gusts blew back in spades as Zolgen used the Holy Grail of this singularity.

"Chaldea! You are much too late to prevent the coming of oblivion upon Proper Human History. So, grovel upon the ground and accept your fates."

On cue, the center of the singularity's storm made its way to Zolgen's side.

"Senpai, visuals confirmed on entity next to Zolgen; According to what I can gauge from here, he's a Servant."

Mash's ever reliable wall of steel materialized in front of us as stray bolts of lightning struck the ground around us.

"Yep, definitely a Servant…" Ritsuka steeled his own guns by his side, "Unfamiliar and unfriendly too even; That's just another bad thing waiting to happen for this."

Looming over us in the air, a long-haired man garbed in purple and black stared us down. Lightning and thunder came and went around him, as he prepared for a showdown.

"Senpai…! His mana levels are off the charts!", Mash took the front position to serve as our vanguard, "He won't be going down so easily…"

On cue, Dantes and J'Alter took a position on each side while Nero guarded the rear. Mordred and Artoria were more than ready to take up the frontlines to this new foe.

"Aside from this guy, I am definitely picking up another presence around here. Not a trace of mana, but I feel something malevolent…", I readied up my own gear for this fight, "This is even worse than Okeanos, but this is a fight for humanity…"

"Come, you Chaldean bastards! You are nothing to us!" As Zolgen shouted out, the Servant from the sky crashed down towards us in a flash. Thunder boomed from the road and lightning crackled about from the epicenter of his landing.

"No way in hell we're letting you come out of this as the victors! We are the hope of Proper Human History and we will see this through!"

Let this battle commence!

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Yes, cliffhanger tease at that end. I know, apologies. Really been a while since I opened up this fic and my interest for it is on and off, so hopefully I can get a good fight scene and epilogue for the Londinium Arc. After this, I'll likely go have a different event rather and skip the 5th Singularity (Not really one of my faves honestly XD) and afterwards, its Camelot time ~ ! P.S. Gonna make a post chapter story longer to make up for its lack in this one ~