This takes place in half life 2 where Barney and resistance are going to initiate the attack in city-17.
Humanity lost the fight 20 yrs ago in 7 hours ,but this time we shall retake our freedom from the Combines.
Barney: what the hell is that!
Unknown resistance member: is that a gate?
G Man: it's time Corporal Shepherd, my employers are eager to see what will happen and so do what you're trained for and smell the ashes....
[In city-17]
Saderan General : in the name of emperor molt! You barbarian's surrender now or face your doom
Random saderan soldier: And then we are going to enslave you!
G Man's employers: This will be interesting.
(Note: it's gate x half life 2, and I always wanted to see Gate anime world reaction to the resistance, Barney Calhoun, Dr kleiner, robot dog, Dr Gordon Freeman, Cpl Shepherd, and small pockets of the remaining H.E.C.U and other government military that escaped and hid after the 7 hours war.
So if anyone wants to remaster this story feel free to do it)
[I don't own half life or gate credit goes to respective owner]