At the top of the hill, we enter a village with a radio tower. We enter an undamaged house on the right; inside are a couple of zombies. The radio isn't working, so we need to turn on the power in the large, ruined building next door.
The large building is closed, but you can climb up the hill from the side and jump from there to the roof. We descend through a hole into a distant, fenced-off room. We take the elevator down to the basement, where we find three sockets and a connecting cable on the far wall. To the right, behind some boxes, we find two more sockets and a short cable. The cables aren't long enough, so we swap them. We connect the two sockets on the far wall with the short cable, ignoring the bottom socket, and connect the two sockets by the elevator with the long cable. Power will be restored in the buildings.
We take the elevator up to a locked room. But hunters begin attacking from outside, gradually destroying one wall. We emerge into a large hall and defeat two hunters. We go outside and fight three more, and two more will arrive a little later.
After defeating them, we go to the house with the communications hub. Alyx contacts White Forest, specifically Dr. Magnusson, but before she can warn him of the impending Combine attack, the connection is cut off, and the image of the alien Advisor momentarily appears and disappears. We drive further through the opened gates.
The small house contains several ammo crates. In a large barn, we knock the padlock off the gate, fall into the basement at the entrance, and crawl to the center. Inside the barn is a metal cocoon with the Advisor, connected to a panel. Alyx decides to shut down the cocoon's power, so we help her by knocking the energy ball out of the generator with the grav-gun.
We miraculously survived, but now Alliance troops have arrived at the Advisor's crash site. The soldiers break down the door and begin storming the building, but we fight them off. Here we gain access to a new weapon – a crossbow. There are a few more soldiers and a hunter outside.
We drive along the railroad tracks, avoiding parked train cars and shooting through standing crates. The helicopter will change tactics: it will fly ahead of us and drop mines. We dodge them by turning onto adjacent parallel tracks. There are two tunnels ahead; we can enter either of them.
Inside, the rebels are trying to fire back at the helicopter, but it's constantly bombarding them with mines. There's no rocket launcher here, but we can shoot down the helicopter by picking up the dropped mines with the gravity gun and throwing them back into the helicopter. We hide from the helicopter's machine gun fire in buildings and under the train cars; we can also find ammo and first aid kits there. Continue to Chapter 5.