Nothing too unexpected happened!
As fierce gunfire erupted, with no warning whatsoever from the troublesome little girl head of state, the investigation team she led—consisting of only twelve Marines—was forced to battle the two or three thousand bizarre metal skeletons in the enclosed, not especially large underground ruin hall.
Of course!
Calling it a battle between both sides wasn't quite right.
After all, no one knew whether those robot-like metal skeletons hadn't fully powered up yet, or whether they were trying not to damage the Obelisk, which seemed so important to them and stood surrounded by the group.
In any case!
Whatever the reason, at first the investigation team was the only side firing, continuously blasting the metal skeletons apart with armor-piercing rounds traveling at ten times the speed of sound.
And soon!
Though no one knew how those terrifying metal monsters had appeared or what they intended to do, the team knew better than to dawdle when they were so badly outnumbered. While the monsters still weren't fighting back, they followed the troublesome little girl and charged through an area with fewer of them, successfully breaking out.
However...
BOOM—!
Just as they had rushed out of the cavernous ruin hall where the Obelisk stood, before the still-shaken group could catch their breath or figure out what had happened, an explosion sent a tremor through the underground passage. The Obelisk had suddenly been blown to pieces?
It was obvious: that had to be the explosive charge the troublesome little girl head of state had planted earlier, either detonated by her or set off when its timer ran out.
And so, when the Obelisk was destroyed, the unsettling metal skeletons, whose eyes had lit up but who had taken no further action, instantly went berserk. They turned as one and charged