"What do you mean by Unexpected Creatures?" Hannah repeated Claire's question to the robot.

Not stopping and continuing down the stairs, Melody said, "They are creatures that seem to have recently appeared, like the Modified Humans."

"Did Star and Moon know that Modified Humans would appear in addition to these creatures?" Claire felt her stomach become sick from the thought of a company knowing the world would plunge into despair and do nothing to stop it.

"Instead of knowing about the Modified Humans would appear, our scientists suspected something would happen when we learned about this new energy," Melody paused, stopping on the stairs, "I guess instead of calling it new, the energy is likely ancient." She continued down the stairs.

Claire was slightly distracted when she noticed a driverless cart with arms driving past the stairs on the level they were passing by. The cart had a flashing light on top of it, as though to alert people of its presence. It didn't acknowledge her presence and kept going to fulfill its task. When she looked back to Hannah and the robot, they were continuing down the stairs, making her run to catch up.

"Due to the way the energy reacted to biological matter, it was hypothesized that the energy would someday affect humans." Melody continued, as though not realizing that Claire had stopped for a moment.

"Then, the Modified Humans are created because of the energy?" Hannah asked. "But if we get exposed to the energy, then wouldn't we turn into those things?"

Melody shook her head. "Modified Humans are not directly caused by the energy, at least that's what we believe. Even though we aren't sure how the Modified Humans started, there are theories about the Modified Humans being like a cancerous cell in a person's body. Instead of enhancing the individual, the energy's interaction with the body causes some kind of uncontrollable chain reaction." She sighed, looking peculiar due to how she was a robot, "In the end, these are all theories since we don't know how the first Modified Human was created. If we were to understand patient zero..." Melody left the thought in the air.

Due to her listening to what Melody was talking about, Claire only just noticed how they hadn't passed by a level in a while. It was as though they were in a tunnel only lit up by the lights on the metal walls.

"Where are we?" Claire asked. "We haven't passed by any levels in a while."

"That's because we're currently passing by levels that normal residents don't have permission to enter. These levels can only be accessed by reaching the lower portion." Melody explained. "This section is mainly focused on combat-related skills in addition to being where we power the entire underground city."

Melody stopped by a screen on the stairway between levels. "I think it's a little hard to understand what I'm saying without seeing a visual." Melody looked to the screen, which had some kind of artwork flowing by. "Show the training area in Section 5," Melody ordered the screen.

A new screen replaced the artwork, showing a wide-shot of the city before it zoomed to a highlighted section of the city with the number five on it. When they could see the current section they were in, another part was highlighted.

"It's nearly the majority of the section," Hannah murmured in awe.

"Yes. Like I said, this section takes care of the training area." Melody nodded her head as she looked at Claire and Hannah. Looking back at the screen, "Show the power source for Underground City 1932345."

The screen shifted the image of the city to below the Training Area. Compared to the rest of the city, there was a slender tunnel that kept going down before finally ending in a spherical area.

"This is where the power is being pulled from. It's deep enough in case something were to go wrong. If there were an explosion, the Training Area would take the brunt of the impact and keep the rest of the population safe. Making the city into separate sectors also adds an additional level of safety. In each sector are large storage areas for holding six months of power in the case," Melody pointed at the sphere, "This thing was to cease functioning."

"What happens if someone tries to gain entry into that place?" Hannah asked.

Melody laughed.

Seeing the robot laugh, Claire wondered whether it was simulated or real. The sight of a robot laughing was a little unnerving.

"Star and Moon has designed each of the shelters to be able to withstand things you can't even imagine," Melody continued to giggle as if the idea was ludicrous.

Melody waved a hand to indicate they should continue down the stairs.

As though sensing it was no longer needed, the screen returned to displaying the artwork previously seen.

"What do you mean about this place being able to withstand things we can't even imagine?" Claire followed after Melody, with Hannah next to her.

"You don't need to worry about that," Melody evaded the question. "If things got that bad, then it'll be over pretty quick." The robot response was ominous in its words.

What made Melody's response seem so ominous was how cavalier she was acting, as though their worries were like trying to avoid a common virus, like the cold or flu. It hinted more towards something eldritch and unknowable.

Not knowing what to ask the robot, they continued walking down the stairs in silence. The lights and stairs the only indication that they were heading towards a direction instead of going nowhere into the earth.

Time seemed to lose any meaning as Claire took each step, her footsteps slightly echoing due to the metal stairs and walls.

In front of them, Melody appeared satisfied by the silence, not picking up the pace and just leisurely following the line next to her.

What made Claire realize they had likely reached their destination was the increase in light in the stairwell.

"Looks like we're here," Melody said in a cheerful voice, as though the extended silence wasn't unusual.

As they turned around the corner of the stairs, Claire saw that the stairs had ended. The ending of the stairs was the entrance into an opening, like the previous levels. Her eyes looked at the differences, compared to the levels they had passed before.

"As you can see, this area has a lot of security compared to the rest of the Sector," Melody pointed at the lanes, "These lanes are meant to prevent casual entrance into the level."

Melody walked up to one of the lanes, where small doors prevented a person from walking through. When the robot was close enough, the doors automatically opened. Turning back towards them, "When you approach the lane, you'll need to scan your bracelet on the blinking red symbol. Come on and try it."

Without hesitation, Hannah walked up to one of the many available lanes. As if she were purchasing food back at the school cafeteria, Hannah placed her wrist on the blinking red area. The scanner flashed red for several seconds before it turned solid green. When the doors opened, Hannah walked through the lane.

Claire had moved to the adjacent lane, copying the motion. Just as with Hannah, the light turned green, and the doors opened to let her through.

"Congratulations. With this, you can now freely enter this area. For those who don't have permission, but want to enter, the light would turn yellow." Melody explained.

"Yellow?" Claire couldn't help but ask.

Melody pointed to either side of the entrance, which had been walled off but had a lane connected to it. "For those who have a yellow light, which means they haven't been accepted or gone through the qualification exams, they'll have to enter an isolated area." Seeing the expression on Claire and Hannah's faces, she brushed it off with a hand, "It's nothing so serious. We have an easy process to determine whether an individual has the ability to gain access to this area."

With that, Melody made her way into the level. Instead of directly opening to the level like the other ones they had seen, this one was like a long hallway. On their way through the hallway, they passed by open room on the left, which had couches and appeared to be a lounge. Melody didn't stop to explain the area, meaning it wasn't very significant.

They soon saw a slight shimmering light, blocking off the entirety of the hallway. It was similar to the first floor with the appearance of the outside world when getting close to the stairway.

"Though we have the lanes which you entered, this is an additional security measure we've implemented. Compared to the lanes, this one can't be bypassed by just hopping over the doors. As we've been walking, your entire body has been scanned and compared to our database." Melody pointed at the shimmering wall, "The shimmering and the green lights around it alerts residents that they have permission to enter. If you didn't, then you wouldn't be able to continue as if it were a wall."

As Claire looked at the shimmering wall, "Why the need for so much security?"

Grinning, Melody said, "Hope you're not here to find out why we have so much security."