In the case of high carbon dioxide concentrations, according to the general analysis, it may be caused by the leakage of the "dry ice" fire extinguisher used to extinguish the fire. However, these are extraordinary times, and it is possible that if there are a large number of organisms in the subway station that breathe carbon dioxide.

So, when a high concentration of carbon dioxide was detected, Raff was a little excited, and fighting the enemy was his long-awaited wish. This time, the third shift brought 7-mm armor-piercing shells, and if there is a "Cerberus" in the dark, it is just right to test how powerful it is, whether it can penetrate the armor of the "Cerberus".

Others, though, weren't excited.

"I don't know if we can meet this time." Briss said that because the previous group of troops also detected the presence of high levels of carbon dioxide, but they released glowing decoys in the subway station and waited for two days, but not a single Cerberus appeared.

"Leave it alone," Craven said in the communication channel, "according to the original plan, if they show up, Briss, Casey, Raf, it's your job to shoot at them—Xu," Craven turned to Xu Xiaoting, "you're in charge of shooting the attack effect in high-speed photography mode." ”

Xu Xiaoting nodded. The X2117A is equipped with a high-speed camera – its left eye is a camera, a feature that other robots don't have.

After arranging the work, Craven unleashed a "spider" robot, about the size of a 20th-century home robot vacuum: a remote-controlled decoy. It can emit light or not, emit visible light and disguise itself as a luminous body, or it can radiate infrared rays and disguise itself as an organism. The "Spider" walks in front of the team and acts as a probe, and its remote control range, which is up to 20 meters away from the wall, and enemies will be spotted when they appear outside 20 meters. The "Spider" has a simple intelligence, and if it accidentally goes out of the remote control range, it will automatically go back a short distance and return to the remote control range.

The first troops, too, used "spiders" as bait. However, it was not able to lure the "Cerberus" into appearing.

The "spider" walked in front, followed by five robots in the third shift. Along the way, they used an extremely long branching cable to extend the signal of the main cable, and then, along the track of the ground station, went all the way east, into deeper darkness - according to the paw prints, that was the direction in which the large number of "Cerberus" retreated.

10m, 20m, 30m, 100m。。。。。。 The five of them walked cautiously, their steps very light, barely making a sound.

200 meters, 300 meters, 400 meters...... Still, there was no unusual noise in front of me.

Until all the 1,500-meter extension cables were used up, not a single "Cerberus" appeared.

"We can't go any further." In the communication channel, Xu Xiaoting said. "There's no signal from any point on."

"Damn it!" Bliss scolded unwillingly and glanced at Craven, "This damn bait really doesn't work?" ”

In fact, when he was tasked before, Briss had suggested using sheep or some living creature as bait, rather than using "spiders" to emit simulated infrared rays to simulate living creatures. Because Bliss suspects that the ghosts won't be fooled, they can tell the difference between simulated infrared and bioradiant infrared.

"We don't have the right to draw conclusions, we're just responsible for documenting what happened," Craven said, "and we're going to go any further, and we'd better be able to scout the entire tunnel today." Craven pointed deeper into the subway tunnel, "We need longer cables to maintain the signal." ”

Craven listened to everyone's suggestions, and then asked Bliss to request a longer main cable, a live sheep, from headquarters. The main cable is used to continue to extend the signal, and the sheep are used as bait.

The 117th Battalion General agreed to the application.

While waiting for the supply, the five robots, Craven, Briss, Casey, Raff and Xu Xiaoting, found the socket from the extension cable, took the robot, and charged it. Kathy, for some reason, recalls the feeling of getting an injection as a child every time she inserts the plug like a robot's body.

While charging, the robot goes into standby, and the operator can take a break. The robots in standby mode are almost unattacked during the Raccoon battle, just like the stand-in robots in the armored patrol car, which are intact after the battle. Therefore, there was no one on duty in the third shift, and all five people left the operation cabin and went out for activities.

In fact, in the combat skills released by the 117th Battalion to the officers and soldiers, there is also a tactic of "standing by and playing dead", in some specific circumstances, the robot can quickly enter the standby state to avoid the attack, so as to avoid unnecessary losses. The mission carried out by the third class this time can be said to be almost stressful, and if you see that the hellhound really can't beat it, then you can, lie on the ground, quickly enter the standby state, and wait until the enemy's limelight has passed before starting the robot.

Craven said that the main task this time was reconnaissance and tentative attacks.

Two hours later, to the roar of helicopters, the 117th Battalion supply arrived in Raccoon City, and the supply was lowered by rope to the entrance of the Fifth Avenue subway station: a two-in-one cable, five boxes, and a relay amplifier, enough to extend the signal for 30 miles; The live sheep that Briss wanted to apply for did not arrive, but they were replaced with live chickens.

Five people carried five boxes of cables, as well as a cage and about 10 live chickens to the subway platform. Raff said the live chickens reminded him of his days serving in the cooking squad.

"Now, it's all robots, and many barracks don't have cooking classes." Craven said to Raff through the communication channel, "So, now that you have a chance to go into battle and kill the enemy, you have to take advantage of this opportunity, and if you have the chance, make those things into a good pot!" ”

All five laughed.

Soon, three shifts of five fighters continued to work: Craven tied the live chickens and spiders together with ropes, then manipulated the spiders, dragged the live chickens, and slowly walked east along the subway tunnel. The rest of the people are busy laying cables, connecting small cell towers, and maintaining the stability of the stand-in robot's signal.

As we all know, in the underground, where satellite signals cannot reach, the two-in-one cable will definitely become the lifeline of robots in future operations.

"I always feel like they're watching us in the dark," Casey whispered to Xu Xiaoting, "I don't know if they'll find out if our weak point is these signal cables." I don't know if it's because she is also a woman, Xu Xiaoting found that Casey prefers to talk to herself.

"It's useless to worry." Xu Xiaoting whispered, "Anyway, my dog often bites off the network cable, grinds his teeth or something......"

The five of them are busy exchanging ideas at the same time, while the "spider" is leading the live chickens and walking in front, this boring task like "chicken" makes people not interested in anything, let alone feel the existence of war. From time to time, there were a few rooster crows in the empty subway tunnel, twisted and weird, like the laughter of a banshee, and only this sound could temporarily awaken the numb nerves of the five people.

"Low nerve excitability, do you activate a pick-me-up?" On Xu Xiaoting's control panel, every short time, such a prompt will appear. The pick-me-up is certainly not a stimulant that is plunged into the flesh, but a perfume that can be sprayed in the operating compartment when needed to help restore consciousness. The reason for the existence of refreshment is that in previous stand-in experiments, some operators fell asleep in the unoperated cruising state and could not wake up naturally.

Generally speaking, the prompt information of the refreshment is turned off, if it is not for the test of the various functional details of X2117A, Xu Xiaoting would not be too lazy to listen to it.

Suddenly, Craven suddenly raised his hand and motioned for everyone to stop moving forward.

The crowd stopped.

(4.22 miles from starting point, Fifth Avenue, action, stop forward) X2117A uploaded log files to the Operations Center.

"What's wrong?" Everyone asked each other in the communication channel.

"Footprints!" Craven said, gesturing to the ground.

(Whose footprint?) The crowd looked in the direction Craven was pointing, and quickly understood what he meant. He is not referring to the footsteps of people, but to the footprints of "Cerberus".

"There are fewer footprints." Bliss held a gun in his right hand and touched his chin with his right hand, thoughtfully. He was the first to grasp what Craven meant.

(Footprints less?) The crowd began to talk in the communication channel. If it weren't for Bliss's mystery, the other three really wouldn't have noticed that there were fewer footprints. Xu Xiaoting had long heard of Briss's acumen, and this was when she finally really felt this acumen.

If it is said that the "Cerberus" that appeared in Raccoon City retreated along this subway tunnel, then, before reaching the exit, their footprints should be equally dense and not less and less, but, judging from the current observation, as the footprints become smaller, it can be inferred that the number of Cerberus is indeed getting smaller and smaller.

"Did they leave the tunnel through some other exit site?" Raff said, "It's impossible to disappear out of thin air." ”

Everyone thought about it and thought it was possible: of course, there were many exit stops on a subway line, and it was natural for Cerberus to leave the tunnel through these exits.

However, in the briefings that the five men had seen before, satellite and battlefield cameras recorded footage of the battlefield: no Cerberus was filmed coming out of the subway exit. In fact, they never came out after seeing them get through the subway entrance. It is for this reason that the military of country A believes that they have retreated to somewhere, possibly, underworld, and may emerge from the underworld again to attack cities outside of raccoon.

Out of an abundance of caution, the five walked back a mile back to the "City Garden" subway station, where "City Garden" was the next stop on Fifth Avenue, where no one noticed the "Cerberus" moving outside the subway station. At Craven's request, the five returned to the "Fifth Avenue" subway station, and similarly, "Fifth Avenue" did not show the footprints of "Cerberus" leaving the subway station. All the footprints are left behind when they enter the subway station.

"So why are they leaving fewer and fewer footprints?" This question is starting to bother everyone.

"Perhaps, they just made a hole and slipped away, so their numbers, and the footprints they left behind, became less and less." Raff muttered quietly in the communication channel. Bliss was then quick to question his idea.

"Punch a hole and slip away? We've been walking nearly 5 miles in the subway tunnel a few hours ago, has anyone seen a 'hole'? Briss said with some disdain, saying that he thought Raff's idea was premature.

The crowd recalled for a moment, and indeed, as Bliss said, saw no holes. With the huge body of Cerberus, they have to make holes to leave, and those holes must not be small, and they should be easily noticed. The fans at the tunnel vents are also intact, not only because of the possibility of them slipping through the vents, but also because the size of the vents is still too small for their bodies.

"I think we should look at the road to see if there are any holes in the road, they are intelligent, maybe they hide the holes." Raff insisted. However, Bliss still disagreed, scoffing at it.

As a result, Craven decides that the five of them will enter the subway tunnel again and walk eastward, until they can no longer see the tracks of the "Cerberus". Moreover, everyone along the way had to carefully inspect the inner wall of the tunnel, the ground, and the ventilation duct to see if there was any such "hole" as Raff firmly believed.

Xu Xiaoting sighed in her heart: Along the tunnel, I have already walked back and forth twice, I feel that this is really a boring task, it shouldn't be testing the endurance of the X2117 type, right? But now Craven Jean went back and had to go again.

In the next few hours, the group of five walked east along the subway tunnel again according to the instructions of Sergeant Craven, and the "spider" robot in front of them led a live chicken, and the tunnel continued to echo with strange chicken croaking. In the communication channel, Casey joked that the mission should be named the "Five-Man Chicken" mission!

(What kind of chicken?) Xu Xiaoting was even more interested, and if Craven agreed, she even wanted to directly turn on the automatic cruise state of the stand-in robot, and let the robot follow the team on its own.

One mile, two miles...... Everyone silently whistled in their hearts, "slipped chickens" in their hands, and slowly walked east.

Before they knew it, more than three hours had passed, and the crowd had already walked more than six miles, and according to the map, they were approaching the terminal. Along the way, everyone carefully inspected the inner wall, the ground, and the ventilation duct of the tunnel, and there was no "hole" in what Raff called it.

What Raff had expected was not confirmed.

However, at this time, what Craven expected really happened. On the ground, all the tracks of Cerberus were gone, and not a single footprint was left.

"Where have they gone?" Everyone whispered.

Craven immediately reported all observations to the 117th Battalion command. After he made a report to the battalion headquarters, the battalion headquarters instructed all the three squads to stand by on standby.

"Maybe the people up there already know what's going on, we're just working here for nothing." Bliss whispered.

"It's possible, but let's just carry out the mission," Craven said, "and there are some things that we should know, and we will be briefed by the above, but if we don't, it's better to know less." ”

"They melt like ice cream." Casey said to herself.

"Or rather, one after the other, they were deleted by God." Raff said, "God hates nothing in hell to get to the ground." ”

The five of them talked in a whisper, but Craven didn't stop it, and Xu Xiaoting guessed that Craven himself must have wanted to know why this happened.

Shortly after the five men were on standby, the battalion headquarters informed further arrangements, and since it was 1 a.m. local time in country A, the third shift could rest. After the DNA identification code will be refreshed and the alias code will be refreshed, the fourth shift will take over the operation of the five robots in the third shift, and the fighters in the third shift can exit the robots and move freely.

"Still free?" "I'm so sleepy, I can fall asleep standing now." ”

Xu Xiaoting smiled.

"I don't know why I really want to eat fried chicken nuggets, or, Xu, in a while, please eat fried chicken nuggets." Raff suddenly invited Xu Xiaoting.

"Then you'll have to send the chicken nuggets to country C." Xu Xiaoting said with a smile.

Raff was speechless for a moment, and then he laughed a few times, and then he realized that he had almost forgotten that the companion in front of him was in fact thousands of miles away.

Sima Aya quit the stand-in robot, and after taking a fragrant bath, she quickly fell asleep, and in the dream, she actually came to the subway tunnel of Raccoon City again.

However, unlike when she was on a mission, now, she is the only one in this tunnel.

"Anyone? Anyone? In a daze, she called out like a silly child lost in the Black Forest.

At some point, Sima Aya saw a faint light in the distance of the tunnel, and the halo gradually became larger, turning into a disc-shaped, graceful like a bright moon. In the bright moon, there is a figure, a graceful woman.

Sima Aya saw that the figure was waving to him:

"Sister Aya, I'm here, Sister Aya, do you want to come over......"

It was Yang Yiyi's voice......