484 Chapter 477. Tower Defense (1)

"What is this? A drill?" 

The people on the base, both espers and guides, looked at the blinking orange light and the loud alarm sound.

"Is that orange? Not yellow?" 

"That's why I'm asking if it's a drill."

The espers were engaging in a casual discussion still, seemingly nonchalant. But they still took out their weapons and fastened their gears. Bassena, who was in the command room until then, materialized behind his first priority; the guides--or rather, Zein.

"What happened?" Zein looked at the esper while giving a signal for the guides to prepare themselves.

"The system detects something coming from the direction of the mountain range."