Inside Kuruoka Tsubaki’s sickroom.
“It looks like... someone — no, something — was just outside,” Jester Karture, still in the form of a young boy, muttered, as if to the girl lying before him.
“Still, when I followed the disease that’s eating into people to its source, I never expected its Master to be a dying girl,” the boy muttered to himself as he stared at the Command Seals on Kuruoka Tsubaki’s hand. He must have somehow snuck into her sickroom after concealing his vampiric face and powers.

Fate/Strange Fake: Volume 3, Chapter 9 ("Day 1, Evening")