They realized that Derry wasn't just a town with a high disappearance rate; the town itself was a feeding ground. Every 27 years, the "It" woke up to feast on the city's children, fueled by their terror. Adults looked away, their minds clouded by a supernatural apathy that made them ignore the screams in the street.
A hypochondriac who discovers that his "medicine" was just a placebo for fear.
The pragmatic skeptic who struggled most to accept the irrationality of the monster.