[X] Telepathically ask your Master to contact Mami and see if she can't get Caster to inform them of the location of one of the Incubator's bodies
-[X] In the mean time check out any location that would house a large concentration of pre-teen girls, such as middle/high schools, and nearby hospitals for any trace of one of the Incubator's bodies in astral form
"I may have a better grasp of this city, but I trust your skills as the better hunter. I'll leave the decision up to you."
"I'll do my best to do you proud, master."
You take a moment to consider your options. In theory, you could attempt to reconstruct a picture of whatever it was that caused these prints, but more than likely you wouldn't get more than the creature's weight and the length of their stride. That's hardly enough to determine if your quarry is the Incubator or the average stray. You could continue the search heading south, but if these tracks don't belong to the Incubator you'd just be wasting time. However, you know by the Incubator's own admission that it's trying to shift the balance of this city back in favour of its own system, so it might be a smart idea to check out places where
puella magi-aged children are likely to gather. Schools and hospitals would be good places to look, in that case.
However, there is still one more avenue you'd like to check before committing to anything.
"Master, one last question before I head out. Can you ask Tomoe to ask Caster if he'd be willing to locate the Incubator for us?"
You wait to hear back from your master, who after a few minutes responds with
"According to Tomoe-san, Caster believes that this is something we can do without his help."
"He seems to be saying that quite a lot, lately."
"I don't envy Tomoe-san for having to deal with him. So what will you do now?"
"last time we spoke, bunnycat let on that he was looking to repopulate the city with new puella magi. I was thinking I'd check out some local schools and the children's wards of the nearby hospitals."
"I suppose those are as good as any to look. Report back to me if you find anything."
With that, you allow your master to return to her schooling. With the next leg of your mission clear in your mind, you plot out the most optimal course for your search to take. East by only a kilometer, the hospital where Sayaka's male friend had been until recently is the closest place on your list to check. From there, you'll head northwest and check out the school up by where Mikuni and Kure live. if both of those turn up negative as well, you'll check off a few of the smaller schools and hospitals on your way back, then return to your master's school and do a sweep of the grounds before calling the search a lost cause. But hopefully it doesn't come to that. Hopefully you can find your quarry before that and wring some intel out of it to bring back to your master.
The hospital smells strongly of antiseptic; you suppose that's a good thing, but your supposings are interrupted by the creaking of the door and a haggard voice that says "Yes, I see. Thank you." It's the man who saved you that night; what's he doing here?
The man approaches, stopping once he has reached the foot of your bed. "Hello. You must be Shirou," he says, bending down slightly so that his eyes can meet with yours. His eyes are dead, and he doesn't look as though he's had a shave in several days. "I suppose I'll come right out and ask you what you would prefer- Being sent off to an orphanage, or being taken in by a man that you just met."
You stare at the man, not entirely sure whether he's being truthful with you or not. He... Wants to adopt you? You try to give his question the thought that it deserves; but despite your hesitation, the choice is clear. Silently, you point to the man. In that moment, you see a flash of colour return to his eyes, and he smiles at you, wider than his wretchedness would have you believing him able to. "I'm glad," he says, kneeling down as he collects your things from under the bed. "Then, let's get you dressed right away. You'll need to get acclimated to your new home as soon as possible. Oh- I forgot to mention something you should know. I have to tell you an extremely important fact."
"Ready?" he asks, muttering under his breath "Yeah, I should do this right now."
The hospital smells strongly of antiseptic; you suppose that's a good thing, but ever since that day, the scent of hospitals has reminded you of the words spoken to you by Emiya Kiritsugu, the words that would set your life down the path Fate had chosen for you.
"You see Shirou, I am a mage."
Your footsteps ring with a heavy echo as you walk through the halls of the children's ward of the hospital, but you're the only one that can hear them. Your eyes harden and your heart aches as you scan through the rooms, but no one can see the scowl on your face nor the trembling of your clenched fists.
Pulled from rubble on the twenty-ninth, fractured legs, internal bleeding; she'll be lucky if she can ever walk again... A young girl that you remember pulling from one of the burning train cars, severe burns to multiple extremities, lung damage from smoke inhalation...
It's not the catastrophic conflagration that ended the Fourth Holy Grail War, but the presence of servants in Mitakihara has changed this city for the worse all the same. Neither of these children should be in here.
Your examination of the children's ward yields no results. Your master will be unsatisfied, but on the inside you breathe a sigh of relief, knowing that the Incubator isn't here to play the Emiya Kiritsugu to these poor children. But, just as you are about to leave, you sense it.
Then you see it, and a meeting between two figures that no one else can see occurs right there in the hall.
"Incubator."
"Archer."