For the next Black Mesa Walkthrough, here is the chapter thirteen : Forget About Freeman. Not like the previous chapter, this one is rather short chapter . Enjoy

First you must dodge the fall ceiling in the corridor, its fall two times, so once you gonna across the way, its gonna fall, and dont go forward, jump aside and it will fall again, jump into the ruins, and crouch to moce forward. Talk to the security guard and listen to the radio. There is a power switch in the room to control a turret. Use it to kill enemies, and disable it when you want to continue.

Kill the enemies on the road and move forward. Take note that the turret will also try to shoot you. Walk towards the doorway marked 38. Turn right and fight the enemies around the corner. Use the valve on the left to open a path to the sewer. Avoid the red lasers and destroy the sentry. Cross the sewers marked East and West. Crouch through the first west sewer and swim forward. Exit the sewer and find the bigger body of water. There will be another ichthyosaur inside of it. Crouch under the giant gear and follow the pipes. Crouch under the second gear and kill the soldiers in the next room.

Destroy the turret and take the ladder to the surface. Turn towards the desert and walk towards the red office. Kill the soldiers in the area. Destroy the tank with your missile launcher. Move into the building marked with Lambda Complex. Turn into the security checkpoint area. Find the sentry in the back of the room and destroy it. Move through the door and into the lift. Take the lift down to the 4th floor. Run through the radiation quickly.

Kill the soldiers by the stairway, but avoid the exploding barrels. Open the door next to the maintenance personnel sign. Destroy the parked tank and enemies in the room. Find the turret in the hall to the right and destroy it. Run passed the jeep and around the corner. Use the button on the wall to open the tunnel door.

Enter the room with the Lambda sign. Enter the control room and throw the power switch. Board the giant lift and activate it. Start your descent on the lift. Neutralize any hostiles on the ground level. Move across the room and up the stairs to the next platform. Open the door and drop down to the dead scientist at the broken rail. Find the room full of shipping crates and be ready to kill the ninja enemies. Since they are very agile, it is easier to kill them with explosions. Move across the room and call the lift surrounded by staircases. Move up the lift. Walk across the catwalk at the top of the shipping room. Break through the crate full of boxes to the other side of the catwalk. There will be one metal door with a green light. Open it and use the lift to descend into the next area.

Thats it for this chapter 13 Forget About Freeman, if you find it hard to follow my instruction, here is the video.