You choose the "Support" route, and then later arrive at the battle zone.
You climb up the stairs of the small building, and equip a Combine Sniper Rifle.
You start shootin' some heads..

After shooting some heads, you crawl up from your status, and go back down the stairs.

After shooting your SPAS-12 a few rounds to get rid of nearby elites, some Rebels arrive.
They tell you about the next plan to evade to the train station, since you can't proceed with Freeman.
You listen to them, and proceed to the train station.

When you get to the train station, you meet other rebels.
Just as you thought things couldn't get any worse beside the fact that there's a hunter invasion happening, a large explosion occurs in the citadel.
Everyone blacks out, as debris falls from the sky. Later, you all wake up, and the sky is a gleaming red.
The citadel has lightning bursting from it.
Instead of going back like the others, you take your own train.

Where should your train go?
PURPLE = EQUIPPED. Inventory:
WEAPONS Combine Sniper, Black Silenced Uzi, 9mm Pistol,
Spas-12 Shotgun, Shotgun Ammo, Empty Boomer Bile Jar, Arms, Medkit.
CLOTHING Camoflauge Armor, national socialist Pig Suit,
Citizen Clothing, Civil Protection Suit, Rebel Armor.
HATS Bonk Helmet.