“I wonder if the people over by the factories are alright.”
“I’m sure they are... See? Look there!” The boy pointed “They all came over here! They evacuated to the city!”
Tsubaki, seeing a large crowd of townspeople headed their way, heaved a sigh of relief.
A little earlier, a sound like thunder had come from the direction of the factories. Tsubaki’s new friend Jester had said that they were burning.
“Oh; if there’s a fire, there must be people. I wonder if they’re OK. I hope they all managed to evacuate.”
Seeing Jester worry made Tsubaki uneasy. That had made her talk to “Mr. Black.”
“I hope the people around the factories are able to get away in time.”
All the while unaware that, behind her, the boy who called himself Jester was wearing a wicked grin.
Thus, the one hundred and twenty thousand people who lived in the area around the factory district contracted an unknown “illness.” While the bloodsucker in a boy’s skin grasped the truth... the city began to roll gently, but inexorably, toward tragedy.
And even he was unaware that, in only half a day, people who would attempt to stop it would appear.

Fate/Strange Fake: Volume 4, Chapter 12 ("Day 2, Morning")