"He means that it didn't suddenly appear in the sense that you didn't notice it exactly when it manifested," says Oat.

"...Yes," says Sindri. "That's what I meant. And if you didn't notice it manifesting, then people can not notice when they manifest, which means that if my parents are really sure I haven't, then there's a way to tell if someone's manifested even if they didn't catch fire or grow wings."

"Or they didn't know that some mutants don't manifest obviously," says Oat.

"Or that. But my parents know a lot of things."