Legend of the Moon Serpent

"MISS LUNA, what exactly are we going to catch?" Kiho asked Luna while silently following behind her. Right now, for a reason unknown to him yet, she brought him in a long, dark, and empty alley. "You weren't talking about real rats, were you?"

Luna stopped walking. Then, she turned around to face him. But her gaze went past him. "Caught them," she said. Then, she raised her palm and pointed it at his direction. "Boo!"

He was surprised when an energy wave was released from her palm. It was too late for him to avoid but thankfully, he didn't have to. He wasn't hit by the strong wave. But he heard some people groan behind him.

Huh?

When he turned around, he was surprised to see two men on the ground.

How come I didn't feel them following us?