Continuing towards the surface, Gordon encounters a terrifying new aquatic creature, the Ichthyosaur, and acquires a deadly new weapon to fight it. After an underwater battle with the creature, he manages to escape and get back on his way.
After battling with the Black Ops, another “rescue” crew trying to kill even the marines, Freeman is captured by the HECU. They remove all of his weapons, and leave him for dead in a trash compactor. Thankfully, Freeman escapes once again, making his way back into the battle.

As Gordon Freeman rides a monorail in the Materials Transport section of Black Mesa, he learns from a security guard that he must ride to the High Altitude Launch Center to launch a satellite, which the Lambda Team can use to reverse the effects of the Resonance Cascade.

He also discovers the HECU’s true hatred for him, as well as larger reinforcements: sandbag bunkers with rapid-fire sniper rifles, mounted machine gun turrets (manual and automated), and even mounted rocket launchers.

After going round in circles, it seems, for a while, he goes up several elevators and at last reaches the surface again. At the launch site, he sends the rocket up into orbit, and regretfully goes back below ground.

Trying to reach the surface once more, Gordon’s progress is thwarted by a clash between a Gargantua and HECU soldiers in the Sector E Materials Transport.

He then learns from a dying security guard that if he restores the generator, he can ride the monorail to the surface. Freeman enters the Houndeye-infested subterranean areas and activates the generator, restoring power to the vicinity.

After activating more switches, he destroys the Gargantua patrolling the area by turning on the huge transformers supplying power to the tram line.
Hitching a ride, he smashes through a barricade of concrete blocks before continuing on his way.

Gordon Freeman enters an abandoned, largely sealed-off area of Black Mesa dating back to its earlier days as a missile complex, full of mothballed machinery and now used as a dumping ground for toxic waste from the rest of the facility, where the HECU soldiers have yet to get a good foothold because of the high concentration of aliens in the area.

This chapter finds Gordon Freeman making good progress, passing through various storage and staging areas, continuing his hunt for a way to the surface. Gordon learns that the soldiers rumored to be coming on a rescue mission have already arrived.

Minutes after the Resonance Cascade, Gordon reaches the office complex, where several scientists are barricaded into their rooms, hiding from the rampant aliens appearing inside the complex.

He then hears rumors from these scientists that the military have arrived to rescue the people trapped in the facility.

As Gordon Freeman’s efforts to reach the surface to get help in the aftermath of the Resonance Cascade just begin, more problems get in his way.

The building starts falling apart in his face, and mysterious alien creatures materialize from thin air. Gordon is given his trademark crowbar, and more weapons and hazards entail.