“…Ah, Father, I bet you’d love to see this for yourself…”


  Reiko muttered those words as she stood before the hatch.

  Back in Hourai Island, the real Jin nodded to those words.

  “…We’ll wait for about a minute after the hatch is opened. Then you go on ahead, sister.”


  Ann explained her plan.

  “Leave it to me.”


  “We’ll follow right behind you if there’s no danger up ahead.”


  “Okay, got it.”


  “I can’t say anything more than that because we don’t have enough information. The only thing I can say is that I want to proceed while avoiding fights as much as possible.”


  There were no objections to that, either.

  “Well, then, I’m opening it up.”


  Ann operated the lever. As expected, it was connected to the hatch, which slowly opened up.

  The diameter of the gaping hole was about 2 meters, which was almost the same as the hatch’s diameter. The lights inside didn’t seem to be on.

  The three of them stood there, 3 meters away from the opening. But nothing happened, nor did anything come out of the hole.

  “A minute has passed. Let’s go in.”


  With her “Peach Blossom” in hand, Reiko jumped into the hole.

  Two minutes later…


  “It should be safe by now. Let’s go too.”


  “Huh? But Mrs. Reiko hasn’t contacted us yet?”


  Alectus was utterly confused. However, Reiko was connected to Laojun via her Mana Comm, and the same applied to Laojun and Ann. Therefore, Ann and Reiko would be able to communicate with each other through Laojun.

  “My sister and I can communicate with each other.”


  That was Ann’s simple answer to Alectus.

  Since there was no time for them to be wasting out there, they concluded the conversation there and jumped down the hatch one after the other.

  It was a vertical hole that went down for about 5 meters. There was a simple ladder attached to the wall, making it look like an emergency exit.

  “Or is this supposed to be some kind of air vent…?”


  The two of them quickly went down the ladder, and found a corridor that spread to the left and right at the bottom. The corridor was bright, as it seemed to be illuminated with Ether Luminaires.

  They could see Reiko standing on one side of the corridor. Apparently, their destination was that way.

  “…But what is this corridor? The walls, floor, and ceiling are made of metal…”


  Alectus’ words came out with a hint of amazement.

  Ann walked silently towards Reiko. Alectus followed her a brief moment later.

  “There are no signs of people around here. There’s a magical reaction a bit further ahead, but…”


  Ann seemed confused by Reiko’s explanation. And Alectus couldn’t help but be surprised at Reiko’s next remark.

  “This metal… I’ve never seen anything like this before.”


  Reiko touched the wall and then stated the results of her analysis.

  “Huh?”


  “I think that even Father doesn’t know about this metal.”


  “So there’s a metal that even the Magi Craft Meister himself doesn’t know about?”


  “That seems to be the case. Makes me wonder who in the world built this?”


  Ann answered Alectus’ question, and a mere second later, Reiko shouted.

  “Stop!”


  “Huh?”


  A door appeared from a nearby wall in front of them, blocking the path ahead. And at the same time, another similar door appeared behind them, blocking the way back.

  “We’re trapped!”


  “Busting through a door like this should be easy enough…”


  Just as Reiko muttered those words while touching the door, a yellowish-green gas drifted from the ceiling. Reiko then made a quick decision.

  “Ann! Stay close to Alectus and create a fully defensive barrier!”


  In response to her command, Ann quickly set up a fully defensive barrier without asking any questions, let alone hesitating. It was a barrier that wouldn’t allow any gas, liquid, or solid substance to pass through. Therefore, it would be able to ward off that seemingly poisonous gas.

  On the other side, it would also set a time limit on the oxygen supply for those within the barrier. Ann didn’t need to breathe, but Alectus was effectively on a timer.

  “…It seems to be some kind of toxic gas.”


  Reiko was able to analyze the gas.

  “…This is definitely chlorine gas.”


  Chlorine is an element with atomic number 17 that irritates the mucous membranes of the eyes and respiratory tract, causing coughing and vomiting. It was used during World War I as a weapon due to its ability to destroy internal living tissue and cause potentially lethal respiratory failures.

  Its special trait is being heavier than air, making it particularly effective against soldiers who were trapped in trenches.

  Sodium thiosulfate (Na2S2O3), also known as “Hypo”, would be needed to neutralize this gas safely, but there was no such thing in this world. (Hypo would be used to dechlorinate tap water in order to make it suitable for keeping domestic fish. Jin knew this, and so Reiko and Laojun also learned this from him).

  “The nozzle is… there. ‘Flame Ball’!”


  Reiko calmly found the nozzle where the gas was coming from, and used a Flame Ball to melt it down and seal it. Next was the chlorine still in the air.

  “…”


  She then contacted Laojun in order to devise a countermeasure.

  “Use water to absorb the chlorine gas, huh? I see… I’m counting on you.”


  After receiving Laojun’s word of advice, Reiko waited for his support. Soon enough, a huge block of ice appeared before her.

  “I expected no less from you, Laojun. I’ll melt this ice first… ‘Heat’.”


  The 1 cubic meter block of ice began to melt into water. Reiko kept on increasing the temperature, causing it to start to evaporate.

  The steam filled the air, absorbing the chlorine gas and becoming a mixture of hydrochloric acid and hypochlorous acid, which was extremely corrosive.

  There, Reiko pulled out her “Peach Blossom” and thrusted it deep into the floor. The unknown metal at her feet could only offer a cardboard-level resistance before the combination of the power of “Peach Blossom” and Reiko’s own strength, and was easily pierced.

  The extremely corrosive liquid went down that hole, rendering the air in the closed corridor completely harmless once again.

  “They’ve underestimated us. Now, let’s open this door.”


  With her “Peach Blossom” in hand, Reiko unleashed a series of four consecutive slashes, two vertical ones and two horizontal ones.

  The metallic door was cut down like paper, creating a square hole in the middle of it. Fresh air came rushing in.

  After that, Ann lifted the fully defensive barrier. Alectus was unable to grasp what just happened, and was just standing there with a confused look on his face.

  “I asked Ann to create a barrier to keep the toxic gas away while I worked on neutralizing it.”


  Reiko offered a very abridged explanation.

  “A-Ah… I suppose I should’ve expected as much from the Magi Craft Meister’s Automata…”


  “At any rate, we can now proceed. We need to be much more careful than ever from now on.”


  The three of them then resumed their exploration of the underground corridor.

  At the end of the corridor, they found another vertical shaft with a spiral staircase leading downward.

  “We have no choice but to keep going down here.”


  Reiko explored the surrounding area with her built-in Magi Detector. Even though hers was a simplified version, it was practical enough at short distances because it helped her determine whether or not there was magical power in the vicinity with certainty.

  “There doesn’t seem to be any magical traps in the area.”


  After saying that, Reiko started going down the spiral staircase.

  The floor below was a mere 4 meters down these stairs. The hallway was also illuminated brightly with Ether Luminaires.

  Nothing dangerous seemed to be up ahead, so Reiko called Ann and Alectus to go down as well.

  “Another corridor, huh?”


  “Yes. Our destination seems to be a bit further down below.”


  “So it’s even deeper underground?”


  “That seems to be the case.”


  After waiting for a minute without anything happening, the party stepped into the corridor that stretched out in front of them.

  The acid that poured from the upper floor was now gone, and the three of them continued walking for about 15 meters before reaching a turn to the right.

  There were no doors on the way.

  “Please stop.”


  Reiko, who was leading the party, asked everyone else to stop.

  From that point on, the color of the floor had changed. What used to be gray was now painted purple.

  “What’s going on here?”


  It didn’t seem to be just an aesthetic change. It was reasonable to think that it indicated some sort of meaningful boundary.

  “Sister, why don’t you try throwing something over to that side?”


  “Right. Let’s see…”


  Reiko’s body had the function of processing, solidifying and storing food. This processed sphere could be shaped into a sphere, which could then be used as a weapon of sorts.

  But now she had chosen to use it for research purposes.

  Reiko spat a small sphere of about 1 cm of diameter towards the purple floor. The sphere drew an arc before falling, and then, the moment it touched the floor…


  “!!”


  Blue sparks flew, and the sphere became charred before crumbling on the floor.