With the advantage of location, Zhao Feng only needed to attack when they got within 1-2 meters.
At this moment, the inside and outside of the passage were two completely different scenes.
Inside the passage, dozens of zombies that had poured in were first pierced from head to tail by an energy beam, and then the energy exploded, blasting apart and spraying all over the zombies still queuing at the entrance slope.
Immediately after, the zombies in the passage had their wounds ignited, and the fire quickly spread and engulfed their entire bodies, turning them into ashes in a short while.
Outside the passage, the upward-sloping exit would periodically eject flames several meters long.
Along with the flames, a large amount of severed limbs and arms, torn into pieces by the explosion, were also ejected.
Many foolish zombies that were still approaching were directly turned into sieves by the minced meat and bone fragments ejected.
In his current state, zombies posed no threat at all.
While annihilating the zombies, the system also continuously delivered the good news of experience points increasing...
Every time the trigger was pulled, dozens of experience points were earned.
【Experience Points +1】x39, 【Experience Points +1】x27, 【Experience Points +1】x36
Stimulated by such wonderful prompt sounds, Zhao Feng was so thrilled he couldn't stop.
Before long, he had killed over 1000 zombies.
Logically, this passage shouldn't be able to hold so many corpses.
But in reality, the quickly ignited corpses burned away rapidly, and the ventilation holes prepared long ago in the room ensured sufficient oxygen.
Of course, this defense system wasn't entirely perfect, and there were still many problems.
Half an hour later, the design flaws gradually began to show.
The first issue to arise was the half-meter thick iron plate passage; its heat conductivity was excessively strong, like an open furnace.
After burning for a full half hour, the temperature inside the safe house had risen to 32℃.
And it was still rising.
Furthermore, a foul, pungent odor had permeated the entire space.
Even with fresh air constantly being pumped in through the ventilation holes, it couldn't be dispersed.
The longer one smelled this odor, the more unbearable and nauseating it became.
It couldn't be helped; zombie bodies aren't entirely made of fat, they also contain internal organs and bones.
The flames needed to completely dry out the moisture within them before they could be thoroughly incinerated.
During this process, a large amount of smoke and gas would inevitably be produced.
The lighter components would float away, the heavier ones would sink, and the more active ones would dissipate into the surroundings.
There was no doubt that this gas was toxic.
If these two problems weren't resolved.
In another half hour to an hour, zombies might not even need to breach the defenses.
The two of them would be the first to be smoked into rotten meat or seared into a "hot plate" meal.
And indeed, that's what happened.
More than ten minutes later.
By this time, Zhao Feng's eyes were red from the smoke, and his previous smugness was gone.
Li Ruolan was in an even worse state; she had somehow collapsed on the ground, gasping for breath with great difficulty.
This situation made him realize he couldn't continue like this.
He glanced at the remaining energy of the drilling laser.
【78.25%】
' Damn it! I'm going all in! '
He turned his head and fired two bursts to kill the approaching zombies.
Then, he nimbly slung the drilling laser onto his back, moved to the side, and pulled out a heavy safety pin.
He raised his hand, grabbed the handle, and slowly pushed open the wall, which was over ten centimeters thick.
The side door he and Li Ruolan had entered through earlier was a secret passage.
The wall he was now pushing open was, in a sense, the true "main entrance."
The purpose of opening the main entrance was simple: to clear the passage.
Fundamentally, the source of the toxic gas was the burning corpses, and they were also the source of the high temperature.
As long as the passage was cleared periodically, poisoning could be completely avoided.
Of course, this operation was extremely dangerous.
But compared to a slow death, a little danger was nothing.
The protagonist tasked with the clearing mission was still the S-type drilling laser in his hand.
Relying on its energy field, which was ejected in its default mode, it could completely clear out the dregs of corpses on the ground, as well as the toxic gas and dust in the air.
It was, in a sense, using poison to fight poison, and "fire" to extinguish "fire."
As the large gate opened completely, a scorching and foul-smelling aura rushed towards them.
What met their eyes was a scene like purgatory.
The passage, originally cast from iron plates, had now become a corridor of flames.
The ground was covered in corpse bones, which crackled and popped in the flames.
The originally black walls were scorched a fiery red, and dark toxic mist rolled overhead.
Enduring the discomfort, Zhao Feng adjusted the drilling laser to its default mode.
With a buzzing sound, an arm-thick red beam was ejected from the gun muzzle.
After half a meter, the light column expanded and diffused, the confined plasma quickly formed a familiar energy field, and completely enveloped the passage.
The burning corpse bones, toxic smoke, and even the foul-smelling toxic gas in the air at the entrance were either annihilated or pushed away by the powerful energy propulsion.
Taking a deep breath, Zhao Feng stepped into the passage.
As soon as he entered, a violent heatwave surged from all directions, enveloping him.
The human respiratory system could not withstand this level of heatwave.
In this high-temperature environment, if you dared to breathe, your nose, throat, respiratory tract, and even lungs would instantly be scorched by the hot air, causing congestion and swelling, and then ulceration.
At the same time, the respiratory system, stimulated to this degree, would trigger uncontrollable physiological responses.
Causing constant coughing and gasping, creating a vicious cycle that would ultimately lead to death.
Fortunately, Zhao Feng had anticipated this before entering and took a deep breath in advance.
After entering the passage, he held his breath completely.
This allowed him to avoid this crisis.
Of course, the damage caused by the scorching air to the human body was not limited to the respiratory tract.
Upon entering the passage, the body's moisture would also rapidly evaporate.
Before he had taken a few steps, Zhao Feng's cheeks were covered in sweat.
His body was relatively fine; wearing the initial protective suit, it could barely withstand the nearly 75-degree hot air in the passage.
However, his exposed face and neck were in agony, licked by the scorching air.
Sweat was almost instantly evaporated by the high temperature the moment it appeared, leaving only salt streaks.
The insulated boots on his feet had already begun to melt the moment they stepped onto the iron plate.
No matter from which perspective, he didn't have much time left and had to finish quickly.
The only fortunate thing was that the resistance caused by these corpse bones was incomparable to soil and ore layers.
Zhao Feng advanced at almost a jogging pace.
10 seconds. In just 10 seconds, he had completely cleared the passage, making it instantly clean.
He then retreated without hesitation.
However, the zombies outside wouldn't let him retreat so easily.
The zombies that poured in again howled madly, ignoring the high temperature inside the passage and the energy barrier between them, and charged at Zhao Feng without regard.
By ignoring the high temperature, they would at most lose some flesh and blood.
By ignoring the plasma ejected by the drilling laser, they would instantly be reduced to dust.
Retreating all the way, the normal zombies, besides crashing into him and meeting their end, didn't cause him much trouble.
It wasn't until the worm zombies entered that Zhao Feng became slightly alert.
As they entered the tunnel, they directly opened their circular mouthparts filled with tiny teeth.
After a brief pause, their abdomens contracted violently, and they spat out a large amount of acidic liquid towards him.
..
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