The moment Lai Mingjie mentioned intercepting similar tragedies, Xu Rouguang had already sent out his senses to locate possible trouble. Aside from his vision, he could also detect spikes in heart rate and the terrified breathing of the targets. He had already located this place from where they were standing while speaking with Lai Mingjie.
He only needed to know why Lai Mingjie wanted him to find these things. If he said something about protecting the peace of the city, the fool of a general would not sleep in clearing the city of its harmful elements. It was never the immortals' business to involve themselves if this was a human against human scenario, but if Lai Mingjie told Xu Rouguang otherwise, the latter would act nonetheless.