The season is SPRING. The cold has finally receeded, and leaves are beginning to sprout from trees. Pokemon are coming out of hibernation and poking their heads out into the world again.
Appearing out of nowhere as the scourge approached, Jericho Circle is Gethsemene City's salvation. It is a barrier grid that surrounds and covers the entire city in a dome. It occasionally emits sparks or spits fire, but it is otherwise harmless to humans and uninfected pokemon. The scourge quickly learned that touching it all completely vaporizes them, but that doesn't stop them from looming en masse just outside the barrier's reach.