『Rankine Magic Ore?』


  『Yeah. It's a peculiar ore that can be made into 『Rankine Magic Crystal』, a material to create powerful mana bombs… The stuff about it being a building material is, of course, a lie.』


  It's clear now why demons went out of their way to employ humans.

  Since Rankine Magic Ore would be polluted and turn useless if anything other than humans try to refine it.

  Demons can get close to Rankine Magic Crystals produced from the refining of the ore, but the refining process itself absolutely needs humans' involvement.

  This property isn't naturally inherent to Rankine Magic Ore, it's a result of the past me casting a large-scale spell that inserted such a property into the ore in the whole world.

  If I didn't do that, demons would have completed mana bombs and the world would have been destroyed by now.

  『Mana bomb… Is that dangerous?』


  『Around one ton of 100% pure Rankine Magic Crystal would be enough to destroy an entire country.』


  I looked around the refinery as I said that.

  The purity seems to be nearly 100%, but at the rate this refinery is going, it probably produces only around 200 gram a day even when it's operating for 24 hours.

  Since there are five refineries of this scale in this town according the the map, in around 1000 days they should acquire a ton worth of Rankine Magic Crystal——the amount needed to destroy a country.

  『One ton, one country!?』


  『…Since this ore is difficult to refine, it's not easy to pile collect a ton of it. It would take about 15 years to create one ton with this refinery alone… Even so, this facility is quite a high level one.』


  Afterward, I look at the machines in this factory.

  In order to refine nearly 100% pure Rankine Magic Crystal, one needs very high level facilities.

  『Y-you're right, the magic device over there looks really complex… I don't get how it works at all… Don't think I could make it…』


  『I can guess its structure somewhat, but it's not something you'd want to make anyway. Tenfold enchanted magic swords are easier to make than that thing.』


  Even if Ruli tried to make one with my design and under my supervision, she wouldn't be able to make this level of refinery machine at her current level.

  And of course, it's also not something the sub-species demons here could have created.

  Either they got a demon with higher level of technology understanding backing them, or they found a refinery machines created by the previous civilization somewhere.

  Magic reactors that destroyed the previous civilization also used Rankine Magic Crystal as fuel, thus perhaps there's some refinery machines made for the reactors lying around somewhere.

  Judging from the apparatus, it seems the demons have remodeled facilities left from the previous civilization to refine high purity Rankine Magic Crystal.

  That kind remodeling is several degrees easier than creating one from scratch.

  "You must be new faces. Let me explain how you're going to do refinery here."

  A man approached us when he saw us standing at the entrance.

  His name tag has 『Factory Manager』 written on it.

  The title is factory manager even though this place is a refinery huh.

  …This guy is not a demon, he's a human.

  I could detect faint traces of demon-like mana from his body, it's probably from a mind manipulation type of spell.

  The underling adventurers are only under the effect of 『Thought Dampen』, but apparently, the one guiding those adventurers are completely under mind control.

  "Is refining difficult?"

  "It's heavy labor, but the process itself is simple. However, there's no change to the fact that it's dangerous. Listen well if you don't want to die."

  Afterward, the factory manager walks to a nearby machine.

  The machine is enclosed within a 5-meter wide barrier, looking heavily guarded.

  "First, put ore into the tank on top of the machine and close the lid. Then push the button here and wait about five minutes for the crystal to come out, and then put it into the casket, that's it."

  The manager points at the button. There's already an ore inside the machine.

  The thing is quite polished as expected of a machine from the previous civilization.

  There were probably other machine thats automatically inserted the ore during that civilization.

  "What's so dangerous about this?"

  "Well… This machine sometimes explodes when you push this button here. About once every 40 pushes. You've got about 10 seconds to get out of the barrier before the explosion, so you'll be fine if you manage to do that… But there's lots of guys who got used to it and were slow to get out in time. There's already four casualties this month alone. Still safer than the mining group though."

  I see, explosions huh.

  There's probably a problem in the remodeling of the magic device.

  Since the machine itself is sturdy, it should be fine even after eating some small-scale explosions, but the people who get swallowed up in the explosion are helpless.

  But still, that's a lot of casualties.

  I can see why the town feels gloomy with that many death.

  And the refinery group is apparently still safer than the mining group.

  Yet the fact that there are still people around in the town must be because of a scheme of the demons. 『Thought Dampen』 is most likely included in it.

  We could stave it off with defensive magic, but the demons would definitely find us out then.

  Since the effect is supposed to stop you from running away due to 『Thought Dampen』, no need to worry about getting influenced by it so long we don't let our guard down.

  "That's it. You can go home once you're done refining all the ore piled up there. Should take around six hours."

  The manager pointed at a heap of ore as he said that.

  That's quite an amount… But it should be done in three hours if we take full advantage of this refinery machine.

  However, they'll suspect us if we finish too fast.

  For now, we should take it as long as the manager said.