There is another hatch for you to pull off. Remove them, and then proceed to the end of the hallway. Once again, soldiers are waiting for you. Some manhacks will arrive to pester you, so take them out, then jump off at the platform opposite the one you came from (it is after the window that Alyx is visible in). After a short trip up, youпїЅre confronted by huge view of the core 8. The main door in the room will now open for you, leading you to an elevator. When youпїЅve taken care of them, go back to the core room and bring a ball in the room, then use it to activate the socket in the room. Once you get into the corridor, there will be some soldiers for you to fight. Get very close to it, then when it shrinks down, walk around it 7. To do this, you have to walk very carefully around the core. You need to get the corridor on the left. When youпїЅre done with them take the energy ball from the battery 6 to deactivate the force field. In the next room, there are soldiers to fight. The exit is on your left hand side at the end. Keep the hatch in your grasp, as you'll need it to block the energy balls in the next tunnel. Use your gravity gun to pull off the hatch on the right side 5. Eventually youпїЅll find yourself at the end of a small hallway. Walk through the hallway the soldiers came from. More soldiers and some manhacks will attack you, but they shouldnпїЅt be a problem. Clear out the soldiers that await, then bring a ball into the room to activate the socket 4. At the top, turn around and walk to the access corridor. Walk to the central platform and climb the ladder 3. Once you reach the end, use the switch you end up at to the move the bridge positions 2. Make your way across the bridges, using another ball for the last socket. Use another ball to activate the socket above you, then the one across the room. When you exit the elevator, take some energy balls and kill the stalkers scattered amongst the platforms. Alyx will call an elevator for you enter it and head down. Once the window opens, enjoy your first view of the citadel core 1. After the core door opens, fight the soldiers that are waiting.

Walkthrough half life 2