Part 40

Follow the winding corridor and stop when you can shoot two explosive barrels ahead. Use altfire hornets to detonate them as a security guard runs by.

Talk to the security guard to make him follow you, then lead him to the corner to the right of the corridor entrance and leave him there.

Wait with an assault rifle for any approaching marines.

Crouch-walk carefully to the corridor entrance, firing hornets around the corner to hit nearby marines.

Continue slowly down the corridor, eliminating all marines.

If you haven't triggered section c2a5e, proceed down the corridor to do so.

As section c2a5e loads, turn around and return to the previous section to retrieve your security guard.

Return to section c2a5e and go to the back of a nearby truck. The turret on the truck should be eliminated by this point; if not, shoot its leg with your pistol.

Enter the truck and bash the crate to find gauss gun ammo.

Move past the truck slowly until something ahead explodes. Have your security guard wait there to avoid him being killed.

Run up the large ramp leading outside, turn right, and run up the smaller ramp.

Hide near the wrecked door until a jet bombs alien grunts.

Crouch-walk slowly to the corner until you can sneak-shoot the turret of a distant tank to the right without it firing at you. Alternatively, use crates against the back ledge to get up and aim slightly above the turret, or use altfire hornets with extreme patience.

After destroying the tank, kill the two nearby marines. You can sneak-shoot them or let them see you and then shoot them with the gauss gun, watching out for their hand grenades.

Break nearby crates for health and armor.

If you missed it earlier, return to the truck to pick up gauss gun ammo.

Go to the destroyed tank, turn right, and proceed to the start of a back alley.

Locate the sniper nest high on a wall. Hang back out of his range and throw a hand grenade at him after quicksaving. Quickrestore and try again if you miss.

Enter the alley and wait for a bombing to occur (it will not harm you).

Find the only open door in the alley. Get out your .357 magnum.

Crouch-walk carefully to the open door, looking left for a marine. Sneak-shoot him once, then shoot him again the instant he runs into view to prevent him from alerting his comrade.

Enter the door and sneak carefully to the corner, looking right for the next marine to sneak-shoot.

After both marines are down, bash the crates in their area for an armor battery.

Head up the stairs. At the end of the upper floor, you will find a security guard and a locked door leading to a supply area.

Get the guard to follow you and stand near the door until he unlocks it. If the guard was killed, return to the guard at the bottom of the big ramp; he can also open the door.

In the supply room, use the light switch to turn on the lights. Run along both rows of shelves to collect items. Bash the crates in the back for additional supplies.

Go to the large window near the top of the stairs. Crouch-jump onto the window's sill, then crouch-walk onto the narrow ledge beyond it.

Move along the ledge to a large light-green machine. Jump from there to another light-green machine.

Take a running jump to the lowest ladder of the broken fire escape. Climb it to reach the fire escape, then climb its other ladder to reach the nearby roof.

(Optional extreme shortcut, not recommended and may be impossible: Cross the roof to the other side, set two laser tripmines on the short wall to use as stepping stones, fall into the helipad area, use the crowbar to bash through the large doors, and run to section c2a5f.)

Assuming you did not take the shortcut, cross the roof to its other side and slowly crouch-walk to the jagged edge.

Look down and use your crossbow's zoom mode to deliver a fatal headshot (a shot that lands on the enemy's head, usually an instant kill) to the marine on the floor below. (It may be necessary to quickly two-shot them before they can alert others.)

Find the large slanty beam leading from the roof to the floor and get on it.

Crouch-walk slowly down the beam until you can see another marine through a doorway ahead and to the left. Use zoom mode to deliver a fatal dart to their head.

Go to the bottom of the slanty beam, turn around, and move slowly toward a doorway with a light on a pillar past it.

The final marine in the area is past the doorway and to the right. Sneak up to where you can sneak-shoot them with the .357 magnum.