It was now the third day since the Portal opened.
The entire Firefly Leaf Valley had become a massive construction site.
Across the plain, more than a dozen kilometers wide, everywhere except Firefly Leaf Town, preserved at the rear, was filled with roaring construction machinery and busy figures.
At the valley entrance facing the Demon Clan, the defensive works had begun to take shape.
Working day and night, over a thousand soldiers had dug three crisscrossing trenches.
The trenches had everything: heavy machine gun positions, mortar emplacements, and Man-Portable Rocket Launcher shelters.
The ground at the valley's outermost edge had been turned over, and countless mines were buried in designated zones.
On the mountaintops flanking the valley entrance, the gray bodies of land-based close-in weapon systems and Land Shield 3000s had been secured in place, their dark muzzles aimed at the sky and the ground.
The prisms of land-based laser weapons reflected faint glimmers in the sunlight, and the surface-to-air missiles had all been deployed.
The same weapon systems had been installed one by one along the mountaintops surrounding the entire basin, creating a network of firepower without blind spots and completely eliminating the possibility of the Demon Clan breaking through from the flanks or the air.
Inside the basin, missile launchers and multiple rocket launchers lay concealed beneath camouflage nets, ready to provide long-range fire support at any moment.
But one fatal weakness confronted everyone in the combat command center: underground!
"General Long."
An operations staff officer pointed at a red area on the three-dimensional terrain map, his expression grave.
"The latest geological survey report is out. The soil structure of the basin beneath our feet is extremely soft. Less than ten meters down, you hit loose rock."
Another staff officer picked up the explanation, bringing up several blurry