Outside the vault, there is a glass curtain wall in the hall, which was protected by a thick metal window after the alien disaster, which is why there is not the slightest sunlight in the hall.

The steel sluice window slowly closed under a slight sliding sound, and the dazzling sunlight shone in.

After adjusting to the light, people's eyes looked out of the window, and one by one they suddenly gasped. Outside the window, there is a huge black vortex formed by the alien hovering, the scene is magnificent and incomparably spectacular.

The vortex rotates counterclockwise at an altitude of hundreds of meters, and from time to time, black aliens like bats join the huge vortex, like moths to a fire. The xenomorphs that were thrown into the whirlpool immediately glided and flew with the whirlpool, and as the xenomorphs kept joining, the whirlpool became thicker and thicker, like a black dragon connected from end to end.

It is not an exaggeration to describe this alien tide as a giant dragon, in fact, at this time, because a large number of aliens hovered in the same direction, a huge air flow was set off in the air, and the air flow actually produced a vortex-like suction, and the dust and shredded paper on the ground were sucked into the sky with the vortex, and also flew with the whirlpool, making the whirlpool appear more and more imposing.

It's a terrible alien tide!

Looking at the darkening sky, Zhou Qing's delicate body was trembling, and a look of fear shot out of his eyes. In fact, it was not only Zhou Qing who looked frightened, but also the five big men and a group of teenagers in Ajing were all sluggish.

Anyone who hangs out on Drow knows the horror of the Alien Tide.

In fact, there are many kinds of alien tides, and the aliens that run wild on the ground also belong to the alien tide, and the low-flying aliens also belong to the alien tide, and when they appear from the cracks in space, they can also form large-scale alien tides.

Among those alien tides with all kinds of patterns, the most powerful is the alien tide formed in an instant after completing the spatial migration from the spatial crack, because, at this time, the alien tide has formed a height of several hundred meters, and if this height dives in a keratinized form, it can form a terrifying impact, and a single alien can crash into a mecha weighing dozens of tons.

In previous battles, the biggest casualty caused by the alien to the human race was the moment it came out of the spatial rift, and the fearless collision without any warning made the human high-tech means unable to work at all.

Normally, the first batch of aliens that came out of the spatial rift were all dead soldiers, and they completely committed suicide by ending up together, so this kind of attack was also the most terrifying, terrifying, and deadly catastrophe. Often, after a round of charges, a city's electric power transportation and communication systems are destroyed, some ground defense systems are basically paralyzed, and many formed ground troops are directly wiped out.

There is no doubt that high-altitude suicide dives are the most primitive combat, but due to their uncertain position, suddenness, and lack of warning, humanity has yet to find a specific way to deal with alien high-altitude dives.

――

"It's over, it's over, a large number of aliens have migrated from outer space to Xicheng District, and we are surrounded." Zhou Qing tried her best to slow down her speech, trying to calm her emotions as much as possible, as an excellent soldier, she knew very well that panic would only make her die faster.

"Yes, we're trapped." The five big men were obviously not as good as Zhou Qing's psychological quality, and they stared blankly at the huge black vortex outside the window, their faces turned pale, and the joy that was still immersed in a billion federal coins just now was swept away.

Among these people, only Liu Fei and Ah Jing remained indifferent, and even the group of teenagers and mercenaries had palpitations on their faces.

In fact, anyone who knows a little bit about aliens knows the horror of the alien tide that comes out of the spatial rift.

The aliens that came out of the spatial rift were more ferocious than ordinary aliens, and they were more fierce and fearless of death. According to scientists, this is because the alien loses a lot of heat energy during long-distance migration, and the alien during this period is very hungry and will attack any moving target wildly.

"It's up to you." Ah Jing's gaze fell on Liu Fei's face.

"No, it's up to you."

"Who just said that they wanted to protect us out?" A sarcastic sneer appeared on Ajing's face.

"If our agreement is negotiated, I will naturally protect you out." Liu Fei's ridicule of Ah Jing was not unique, and his face was calm.

"I'm just as good as them, and if you can get me to Dongcheng safely, I'll only need a billion federal coins, but if you can't provide protection, or let me fight, then the agreement between us won't be binding." Zhou Qing hurriedly said.

"Of course." Liu Fei glanced at the growing whirlpool outside the window.

"Okay, that's a deal."

"I don't believe you." Ah Jing snorted coldly.

"Ah Jing, even if he hides in the basement, it is impossible to survive this alien crisis." Liu Fei looked at Ah Jingdao with a blank face.

"Ahh Ah Jing's face changed color, he couldn't imagine that Liu Fei actually guessed his intentions.

"From the current point of view, for some unknown reason, this building is the base camp of the aliens, when you stormed the building, killed a large number of aliens, there is no doubt that your actions alarmed the high-level aliens of this building, they organized a series of encirclements, however, this encirclement was broken because of my appearance-"

"Your appearance! Hahaha-" Ah Jing flicked the long knife in his hand and laughed, and the laughter was filled with endless contempt. "You mean to say that without your presence, we'd be surrounded by aliens?"

"Yes."

"I'd like to hear how you saved me."

"When you climb up from the first floor, the more aliens you go up?"

Ah Jing opened his mouth, glanced at a group of teenagers and did not speak, it was obvious that Liu Fei was right.

"As the floors get higher and higher, there are more and more high-level aliens, and at the same time, you have casualties, right?"

"-Yes!" Ah Jing hesitated, but still nodded, he is not a person who is good at lying, not to mention, the facts are in front of him.

"Just when you couldn't bear it anymore, the number of aliens suddenly decreased, and when you got close to the 150th floor, the aliens disappeared completely, do you know the reason? Because, I know that you are below, so I sent someone to guard the staircase to intercept the aliens, and you must have seen the mountains of alien corpses. ”

"It's just a coincidence." Looking at Liu Fei, who was not a few years older than himself in front of him, an inexplicable chill rose up on Ah Jing's back, this person was so terrifying, his every move was actually in his calculations.

"Coincidence? Hehe, we have at least dozens of ways to block the door of the fire escape. Liu Fei's eyes swept over the alien whirlpool outside the glass curtain wall.

"You're trying to tell me that you saved us!"

"No, I'm just telling you, it's useless for you to avoid the alien tide, the aliens won't give up this building, and besides, the aliens that form the alien tide in the sky don't migrate from outer space, they are all born and raised in Drow, and the aliens are native-"

"As far as I know, aliens are not capable of flying at high altitudes, and if they are not migrating from outer space, then are they any that fly hundreds of meters into the air? We're on the 150th floor now. ”

Ah Jing glanced at the increasingly terrifying black vortex outside the glass curtain wall, and slowly retreated towards the vault, while a group of teenagers followed and retreated towards the vault.

Seeing Ah Jing retreat towards the vault, the five big men and Zhou Qing also subconsciously retreated towards the vault.

The atmosphere became tense, because the edge of the black swirl was almost close to the glass curtain wall.