MAP 12: THE SOURCE WALKTHROUGH if you need more help, visit the SM forum HERE or Download a PDF VERSION HERE

Map 12: THE SOURCE begins with a locked gate. Enter this room and pull the lever in the corner. Fight your way down the hallway and look for this ladder just past the door where the combine run out.

Use this button to open the massive strider door. Oh and just ignore the "no strider" sign for now! After the fire fight, open this door.

Take out these enemies and then look for a ladder just to the right of the room where they came out. After the cutscene showing the strider being put together, you finally enter The Source of the Striders. This room needs to be destroyed in order 1, 2, 3,4. Here's how:

Take out #1 Reactor. Climb up the ladder to #4 Reactor and look for this door. jump down and pull the lever to enter. After a cutscene, this door is now open.

Enter the room and look for this vent shaft. This is the location for the EASTER EGG. Now climb the stairs to #3 Reactor and then look for this open door. Jump down and enter the room.

Once inside the room, pull this lever. And the locked gate where the turret was location is now open. Head in and climb the stairs to the left.

Now you access to #1 Reactor and stairs to #2 Reactor. Press the box on the right and a count down will initiate. Then press the detonator on the left to shut down the reactor. Repeat this for all 4 reactors.

To take out #3 Reactor, go back up these stairs. Repeat the steps in #1 and #2 Reactor to melt down #3 Reactor.

To take out #4 Reactor, look of rhtese stairs at the end of the hallway. Then climb this laddrer to reach the catwalk.

Now that the source is destroyed, all hell is breaking loose. Run out of the chaos and look for this ladder to higher ground.

Run across the catwalk and in this room you'll the RPG and ammo. Take out the Strider. After the battle, look for this ladder on the roof.

Make your way across the catwalk, take out the remaining combine and jump down to exit The Source through the TUNNELS.