It was an unspoken rule that no activity concerning the War was to happen during the day. There were far too many people around, and the fact that everything was illuminated made it basically impossible to hide something as flashy and destructive as a Servant battle. The general wisdom was that the War started at sundown, and if you hadn't managed to achieve anything by the time the sun rose, well, that was you done for the night. The Master would retire to their base to wait out the day, catch up on some well-needed sleep, and prepare for the next night.

But… it still wasn't an actual rule.

The rule – and it was really more of a guideline anyway – was that you weren't allowed to reveal the existence of magic. That was it. And in that regard, an Assassin could get away with a lot that another Servant couldn't, even in the middle of the day.

As a spirit, she was invisible to all without some kind of magical senses, and it wasn't like the Presence Concealment skill checked whether or not the sun was shining, so Servants wouldn't notice her either. Like all the other Servants, if she got in a fight it'd be immediately noticeable… but, then, why on Earth would she choose to do such a thing?

So. It was early afternoon, and Serenity had just finished shadowing Tohsaka back to his house. As before, she stopped short of actually crossing into his property – she was almost certain her Presence Concealment was proof against anything he had set up, but… you never knew. Why risk it?

Master? she asked.

Yes?

Are we planning on supporting either side during this hunt for Berserker? Kiritsugu hadn't said anything on the matter. There was nothing wrong with that, of course… but Serenity had gotten used to immediate and clear direction from her Master. To not have that on such an important issue was… unusual. She decided to prompt him. Her expertise was considerable, and her Master had made sure she knew he valued it. Enabling Archer to kill Rider with a Command Spell seems like something we should support, but…

The last conversation between the moderator and Tohsaka suggests there is more to it. I agree. Her Master's voice was cold as ever, but over the telepathic connection, he couldn't quite hide his nervousness. I assume Lancer is Kotomine Kirei's Servant. No, he must be. To have formed an alliance already, Tohsaka has not had a chance to contact anyone else. And Tohsaka believes this Lancer capable of standing up to Archer's Noble Phantasm, even boosted by Command Spell… Assassin, we must find Kirei. No other Master is so dangerous.

Serenity wasn't sure, even now, what had Kiristugu so worried about this Kotomine, but her place was not to argue. Yes, Master. And… the other Servants?

There was a pause while Kiritsugu thought. …yes. Tohsaka has made them relevant, by bringing them into his game against Matou. Lancer… This time, her Master's thoughts were flavoured with frustration. …will wait. Clearly Tohsaka intends to keep him in reserve. Very well. Assassin, monitor the other Servants. Discover their identities if you can. If you can locate Berserker, do so. I will… make a decision on what to do.

Very well, Master. Serenity set off. Her Master hadn't told her where to start, but, of course, Serenity was fully informed as to the current disposition of all known Masters and Servants. There was no point in keeping her in the dark, so Kiritsugu shared all information with her, allowing her to make informed decisions on the ground.

Like now. Invisible, silent, Serenity hopped from rooftop to rooftop to sprint down a deserted street, to leap and swing and land back on the rooftops again. She had never been to her destination in person – but she'd seen photographs, and she'd looked through a map of Fuyuki, and that was enough.

The city was… different, during the day. So many people – they thronged in the streets, and the next street over would have more, and the next street as well, on and on as far as the eye could see. Fuyuki was, the Grail informed her, a small-ish but growing city. In her day, it would have been, by far, the largest city in the world.

People out shopping, or relaxing with friends in the sunshine, or just walking as far as Serenity could see. You'd never know that each and every one of them was under threat from spirits that should never have existed in their peaceful time. It was relaxing and humbling to behold… but melancholy at the same time. Even had Serenity's body not been cursed so, she could never be part of this sunlit world where everyone was smiling.

No. She was here to kill for her Master, to make sure this world endured.

Up ahead, the Hyatt came into view.

It wasn't actually all that hard, to find out who was selected as a Master. At least, not the ones selected from the Association. The Grail assigned Command Spells however it wanted, but there were certain trends, and the sheer number of magi who made up the Association meant that more often than not, the leadership could be said to have a 'candidate' to present. They weren't guaranteed a spot in the same way that the Founding Families were, but it was a pretty safe bet.

And, well, magi being magi, if one of the traditionalists was selected for an honour that set him above his peers, you'd damn well hear about it. Kiritsugu didn't even have to do anything – the Einzberns had long established the infrastructure for this sort of thing. In this case, they had plenty of contacts within the Association that had let them know the moment Kayneth Archibald El-Melloi started bragging.

From there, it was a matter of monitoring his movements. El-Melloi was reportedly an expert in spiritual evocation and summoning, and just generally a talented magus all-round, so he was very likely to notice any magical tracking attempts. No doubt he dealt with that kind of thing all the time – the Clock Tower was notorious for underhanded dealings, and someone as important as the lord of the Minerology Department must have people trying to steal his research as a daily annoyance. He would spot any familiars or sympathetic connections from a mile off.

He would probably not, however, do the same with the local private detective hired to note his arrival in the country and discreetly follow him to where he would be staying. Magi tended to lose all sense for mundane matters, and forgot that the vast majority of the population got along just fine with no magic at all. El-Melloi had proceeded blithely to his hotel, and the slightly confused P.I. had reported in on this – and a couple of other matters – been paid for his time, and sent on his way.

He hadn't managed to actually get in to the room itself, of course. Dismissal of mundane methods or not, El-Melloi wasn't that stupid, as Serenity discovered when she attempted to access the room normally. (You never knew.) He'd locked out the entire floor, in fact, involving some really complex space-warping that allowed the stairwells and elevators to bypass the whole thing unless it detected the correct magical signature.

The floor itself had been transformed into a labyrinth, with more space warping messing with the dimensions to the point that some of the doors led into alternate dimensions altogether. There were traps and tripwires and effects laid over what looked like every inch of the place. More, there were what felt like at least a dozen ghosts, spirits or demons wandering around looking for intruders, with various sensory abilities and various hunting patterns. The place was impossibly secure.

So much so, that it wasn't even security any more – to Serenity's eyes, it was just showing off. Almost childlike, in fact, in the caster's clear excitement and anticipation of someone trying to get past all his clever preparations. No-one did all this just because they wanted to feel safe, War or no War. No, it looked like El-Melloi was here for… a good time? He wanted to match wits against other magi, each of them using everything they had, and prove he was superior.

Well, blow that for a game of soldiers.

Serenity might well have been able to work her way through the maze of traps. The combination of dematerialisation and Presence Concealment at A+ rank did a lot to deal with pretty much any combination of sensors. El-Melloi would have been expecting that, of course, and set countermeasures specifically for Servants, but Serenity was one of the best in history at what she did and she was reasonably certain she could cope.

But, really, that sounded like a lot of work, and why bother? There were easier ways of doing this.

Serenity stood on the very edge of the roof, enjoying the afternoon breeze through her hair. Crouching, she drove two knives up to the hilt straight into the concrete – on the vertical side of the building, over the edge. Keeping hold of each knife, she leaned even further over, then picked her feet up and straightened out into a handstand, holding herself over empty air.

Then she pulled one knife out and lowered herself on one hand. In went the free knife, a little lower.

Step by step, she lowered herself down the side of the Hyatt.

See? Much easier.

Even like this, she kept her mental map of the internal layout of the Hyatt. When she judged that she was above the right window, she bent her arms and lowered her invisible head so she could just peek through the top.

The Hyatt was grand and luxuriant – well, most modern living spaces seemed that way to Serenity, although she was aware she'd so far lived in two castles and spent her time observing a mansion, so she might not have had the best sample size to work with. But the Hyatt was luxuriant and modern, rather than old-fashioned – all wide and open-plan, curving walls, lots of glass. Interesting.

But she wasn't here to examine the architecture. Serenity held still as two people came into view – one a blond man in flowing blue clothes, the other a redheaded woman in a white blouse with a ribbon. They seemed to be in the middle of an argument, or at least a one-sided rant on the man's part.

Serenity recognised El-Melloi, but wasn't familiar with the woman. She didn't set off Serenity's sense for Servants, although something in the apartment sure was – though whether they were dematerialised or simply out of sight Serenity didn't know.

Master, she sent, knowing that Kiritsugu would focus on seeing through her senses. Any idea on who this woman is? She could be an aide or confidante, but she doesn't act like either. If anything, she seems to be an equal to El-Melloi.

Do you have a clear shot at him? came the reply at once. There's no point in collecting information if we can just kill him and get him out of the way immediately.

No clear shot, Serenity said. Not without knowing the whereabouts and capabilities of his Servant.

Keep listening, then, said her Master. I'll see if our files on El-Melloi have anything.

Serenity did so.

"… that little upstart thinks he is," El-Melloi was snarling. "Bad enough he defies me, but that the Grail should grant him Command Spells also? As though we were equals? And to add insult to injury, the Grail decides to grant the Servant of the Spell to such an insolent fool. Tell me, Sola-Ui, if the Servants summoned are a reflection of their Masters, what does that say, that the brat's ego called to such a master magus?"

"It tells me you are being ridiculous, Kayneth," snapped the woman – now identified as Sola-Ui. "If we had swapped Servants you would instead be complaining that this Waver Velvet drew the most outstanding class. Has Saber given you any cause for dissatisfaction?"

"No… Saber has been exemplary, I admit. But it irks me, Sola-Ui, it irks me that Velvet's Servant refuses to come out and fight. Sending automatons against me… surely they cannot think to defeat me with toys? But if not, what is his design…"

Sola-Ui rolled her eyes. "You're getting obsessed. Velvet and Caster are a non-issue, surely? No Caster can stand up to Saber, and were you to take the field against Velvet… well. Enough said on the matter. Focus on something else. Such as this situation with Berserker."

"Hm." El-Melloi sat down on the couch, and reached for a bucket of wine and a glass. "I'm torn on that. Part of me wants to let Matou and Tohsaka destroy each other and take out Berserker into the bargain, but… having the extra Command Spell would be useful."

"Would you use it to support Tohsaka or Matou?"

"I haven't decided yet." El-Melloi smiled. "I suppose it would depend on who can give me a better offer."

"Or on whose Servant would otherwise give you more trouble."

"… yes, there is that." El-Melloi swirled his wine. "In any case, even just having the option would be helpful… and it has been dreary, cooped up in here. This is hardly what I was expecting from the War."

Sola-Ui frowned. "Think how it's been for me, will you? At least you have full access to your magic, and can go out and fight alongside Saber… not that you have," she sneered. "I, on the other hand, will stay here for the rest of the War. Honestly, the things I put up with."

El-Melloi smiled, and to Serenity's eyes there was genuine affection there. "Yes. Thank you once again, Sola-Ui. You know I wouldn't be able to do this without you, do you not?"

The woman rolled her eyes and turned away. "Yes, yes. I'm not objecting, really. But it's frustrating, to be dragged into your scheme and then for you not to even take advantage of it."

"Well, just because you're providing all the power to keep Saber active doesn't mean I have to waste mine. There's no point in setting up this grand atelier and then not making use of it. I'll engage, carefully and in a time and place of my own choosing. If I'm fighting, I can at least fight as a magus does."

"Seems to me that a magus fights very similar to a coward," Sola-Ui spat. El-Melloi blinked, clearly taken aback.

"What would you have me do, Sola-Ui?" said El-Melloi, his tone slightly mocking. "Pick up a sword and charge in alongside Saber? I'm no good at that, and it's not my place. Now who's being ridiculous?"

"How dare-"

The door into the apartment flew open, and in swept a knight in pale blue and white, proudly bearing what looked like a broken clockwork bird.

"I have finished!" declared the knight, brandishing the bird like a hunter with a pheasant. "It gave me trouble, oh yes, but once again the Knight of White Lilies is victorious over Caster's silly dolls!" Then, appearing to notice the atmosphere in the room for the first time, continued, "…am I perhaps interrupting something?"

El-Melloi was the first to break the silence. "No, Saber, not at all. Sola-Ui and I were merely having a disagreement."

"Ah, the usual issue?" The knight – Saber – smiled, apparently familiar. "My Master, I well know how troublesome women can be. But I urge you to see my lady's side as well. You are talented, likely the most talented Master in the War. With such talent should come gallantry, or what is it for? Let us sally forth, the most magnificent and amazing Master and Servant, and dazzle all with a display of our skill!"

Sola-Ui gave El-Melloi a hard look. "You see? Saber thinks you're a coward as well."

"Not at all!" cried Saber, seemingly distraught by the prospect. "Master, I am your knight, to use as you see fit. As I served the Royal Family of France, and as you serve your Association, I now serve you, and to do as you command my only desire. I only mean… do you not want to fight alongside me? Were you not dissatisfied with not engaging the foe in the cut and thrust of battle?"

El-Melloi started to say something, but paused, closed his eyes and sighed. "The two of you are impossible. Saber, Sola-Ui, I'm only trying to conduct myself as a magus should. Of course I want to stride onto the battlefield and use every code, spell and trick I have to emerge victorious. But, Saber, though we fight with honour, others will not." He gestured at the broken automaton, still held in Saber's gloved hand. "Our foes would not hesitate to strike me down should I show myself on the battlefield. Through treachery, through trickery, through some means I can only guess at, I would die – not in battle, but through my own foolishness. And our chance for a wish upon the Grail will be lost. Is that what you want?"

Sola-Ui looked away in disgust, but said nothing. Saber's head shook emphatically.

"But…" El-Melloi continued. "Perhaps it is time I took a more active role in the War. Come, Saber. I have made my decision. We go to hunt Berserker! With my spells to track them down, and your sword arm, we cannot lose. Make your preparations. We leave at nightfall."

The look on Saber's face was radiant. "Yes, Master! For France, for the Association, we shall not fail! En garde!"

El-Melloi and Sola-Ui disappeared into the apartment, while Saber remained.

Your assessment, Assassin? said Kiritsugu.

Very straightforward, replied Serenity. And El-Melloi's focus on Waver Velvet and his Servant Caster may be a distraction we can exploit. However, you should not face El-Melloi in direct combat, Master…

Agreed. I never intended to. And Saber?

The Knight of White Lilies… Chevalier D'Eon, Serenity recited the information fed to her by the Grail. Not the most powerful… but skilled. Of the Servant encountered so far, likely the most talented in combat, just as El-Melloi is the most accomplished magus. However, Master, El-Melloi is not a threat. He will not be difficult to kill.

Explain.

Serenity focused on the coffee table, where the bottle of wine still sat in its bucket of ice. No matter how great your fortifications, or how secure your quarters, you still need to eat and drink. It would not be the first time, or the second, or the fiftieth, that I poisoned the food sent to a target.

I see. And if all else fails, there is still the fallback plan we discussed.

Yes. Serenity wasn't a fan. For one thing, blowing up a whole building to get to one man was… well, it just seemed a bit flashy. To be sure, it would probably be effective. There weren't a lot of spells one could cast immediately that would protect you from a fifteen-story drop unless you were expecting that kind of thing – and you had to be a special kind of person to anticipate someone taking out the floor from out underneath you.

But there was a bigger reason Serenity wasn't sold on this plan. As her Master laid it out, he took great pains to explain how he would keep the people of the hotel safe. He would set fires on the lower floors, he would ring the alarm bell, he would wait until El-Melloi was the last name to be called and impersonate him. It would allow the building to be brought down with only the magus inside.

When Serenity had asked, matter-of-factly, why he did not simply detonate the charges with no warning, to reduce the risk of El-Melloi having, by chance, prepared some defence, he'd chuckled to himself and said he must be going soft. Serenity didn't believe him.

Of all the times to begin considering collateral damage, it was during this, the most important fight in – potentially – the history of mankind? With the wish for eternal peace at stake, why take the risk? Why refuse the sacrifice?

No. To Serenity, this only confirmed what she'd thought. Silently, she fell forward and off the side of the building, fading into shadow and descending as a ghost.

Her Master was cracking under the strain brought on by the conflict between his ideals and what he had to do to reach them. With his hands covered in blood, with his goal so near, he was finally beginning to balk at what must be done.

Serenity could not allow that to happen. She had to support him with all he had, stop him from having to make the hardest decisions by making them irrelevant.

Or Kiritsugu would break, and the chance for a better world would be lost forever.