“Commencing bombardment experiment.”
A group of multi-legged tanks deployed outside the Holy Capital, roughly one kilometer from the city wall, trained their turrets on it.
“First shot, fire.”
A flash burst from the muzzle. An armor-piercing round wreathed in plasma flame was fired toward the city wall.
The steel warhead was blocked by the deployed magic barrier.
The warhead struck what amounted to a perfectly rigid surface head-on, underwent plastic flow, and shattered into fragments.
“Measuring effect. No impact whatsoever observed.”
The magic barrier protecting the city wall had completely nullified the shell’s power.
Of course, this phenomenon had been expected from the beginning. They had already conducted exhaustive performance tests on the barrier.
“Now, now, Big Sister, next! Next!”
“Calm down, Asahi.”
Watching the test were Asahi, so excited that she was practically shaking, and Eve, who had an arm around her shoulders to hold her still.
Akane and Olive were seated at the operator stations, watching the incoming data.
Ichigo, Utsugi, and Erika were in the rest area at the rear, enjoying the tea service <Ringo> had prepared.
“Second shot loaded. Selecting burnstone warhead.”
And this was the centerpiece of the current experiment.
The newly developed burnstone warhead.
A burnstone warhead was, exactly as the name suggested, a shell with burnstone built into the warhead.
A burnstone lump of roughly one kilogram was covered in a heat-resistant coated steel casing and built into the tip of the warhead.
“Second shot, fire.”
At <Iris>’s words, the burnstone warhead flew from the muzzle.
The shell, flying at a supersonic 2,000 meters per second, struck the city wall directly.
The burnstone warhead collided with the deployed magic barrier, was crushed between the collision surface and the steel mass of the warhead’s tail section, and, true to its properties, released the heat contained within it.
A flash.
The burnstone lump, compressed in an instant, vanished while producing an ultra-high temperature approaching 10,000°C. The molecules around it turned into plasma and emitted a violent light.
“Hit. Measuring effect.”
Naturally, a single shell was not going to do anything decisive to a magic barrier protecting the entire Holy Capital.
But its effect was completely different from that of a standard warhead.
“Partial damage confirmed on the surface of the city wall. The surface has vitrified from the heat radiated by the burnstone.”
“Ooh!”
“We did it, Big Sister!!”
Astonishingly, the heat generated by the burnstone had pierced through the magic barrier that was supposed to block all energy and reached the city wall inside.
It was something their experiments had already allowed them to predict, but confirming its effect in the form of an actual shell was significant.
“A fairly large amount of heat seems to have gotten through! If the surface vitrified, it must have reached at least around 800°C! That’s more than enough to count as damage!”
“So kinetic energy really doesn’t get through, huh... But if this much heat goes in, even just landing several hits should make for a solid attack.”
“Calculation complete. At least 20% of the thermal energy is believed to have reached the city wall.”
<Iris>, who had been analyzing the sensor information, reported the result.
“However, the burnstone’s effect lasts only about 0.1 seconds, and its damaging effect against large threat organisms is limited. It lacks sufficient power to serve as a decisive blow by itself.”
“Hmm. Well, yes. Basically, it’s just roasting the target with infrared radiation, right?”
“Correct. Next is the barrier durability test.”
<Iris> answered calmly, then began preparing the next test. The engine output of the land battleship on standby rose, and it slowly began moving into firing position.
“We’ve run durability tests with standard shells any number of times, so the first part is just confirmation! Though there does seem to be some margin of error!”
“You are going to avoid breaking it when we have to dig it out and reuse it, right...?”
“Standard shells will not pose a problem, but burnstone shells carry a risk of city-wall collapse.”
<Iris> answered Eve’s worried remark that way.
Eve looked startled and turned back toward <Ringo>.
“Yes, affirmative, Commander Ma’am. <Iris> has already calculated it, so there is no issue. There is only a minimal amount of monster tissue inside the targeted section of the city wall, and even if it collapses and the monster tissue in that range is lost, it will not hinder transplantation to the front-line fortress.”
“...I see. That startled me. Then, <Iris>, you’re saying there is a risk, but it won’t be a problem?”
“Affirmative. Even if every shell used in the test strikes the city wall, the destruction range will be limited. It will have no effect on future operational activity.”
“Understood. Then let’s get it over with. Once we finish digging out the monster tissue, we probably won’t be able to run tests like this again for quite a while.”
“We don’t have any samples where we can verify a magic barrier, after all! The <Rain Croin> juvenile is still growing and weak, and actually luring in a wyvern would be far too frightening!”
Eve reacted sharply to Asahi’s cheerful voice.
“Obviously! You absolutely cannot lure one in, do you hear me?”
“Nngh... Even Asahi wouldn’t be reckless enough to go that far...!”
As Eve kneaded her cheeks back and forth, Asahi made a feeble protest.
Apparently, even she was aware of it.
“Commencing bombardment.”
Leaving that little comedy aside, <Iris> proceeded through the experiment protocol with cool precision.
The land battleship that received the bombardment-start signal began firing with the batteries installed on its port side and centerline.
“Barrier neutralization confirmed.”
The barrier, which had been glowing as it stopped a large volume of shells, lost its effect. Through strictly controlled bombardment, the barrier had been precisely neutralized while causing almost no effect on the city wall.
The original device was biological in origin, so its barrier strength did fluctuate depending on the moment. Taking those fluctuations into account, <Iris> had predicted its strength with considerable accuracy.
“Confirmed result matches projections. Holding until the barrier recovers effectiveness.”
It took only a few seconds for the magic barrier to redeploy, but it required time to recover its maximum strength.
On top of that, they had learned that a rebound-like phenomenon also occurred, so it was better to wait around ten minutes for it to stabilize.
“This is a test to see how the barrier’s durability value changes when we use burnstone warheads, right?”
“Yes, Big Sister. Next, we plan to measure the result when all shells used are burnstone warheads.”
“If we find a significant difference, we’re also planning tests mixing standard warheads and burnstone warheads to see how the result changes by ratio!”
Incidentally, the amount of burnstone to be used in this test equaled half the total weight traded with foreign countries over the past year or so.
If burnstone warheads came into full-scale use in the future, the trade officials of the Kingdom of Lepuitari would likely faint foaming at the mouth from the sheer quantity of burnstone consumed.
“Scheduled time elapsed. Commencing bombardment.”
And then <Iris> pulled the trigger.
The warheads fired with slight time differences struck the city wall in succession.
“Barrier neutralization confirmed.”
In the relayed footage, the magic # Nоvеlight # barrier vanished as if bursting apart.
With nothing left to stop them, several shells plunged into the city wall. They collapsed the fragile stonework while releasing their enormous heat.
“Measuring effect.”
“Ah. It collapsed...”
A stone-block city wall did not have enough strength to resist shells colliding with it at supersonic speed. Because the burnstone warheads were softer than standard shells, their kinetic energy penetrated deeply enough. The ultra-high temperature they then generated heated the surrounding stone, vaporizing fine fragments and sending some of the rest scattering as it melted.
“More shells than projected struck the city wall. Initial analysis result: the magic barrier was neutralized by approximately half of the fired burnstone warheads.”
“Big Sister, Big Sister!! Amazing! That barrier collapsed from just this much! Wait, <Iris>, you recorded it properly, didn’t you?!”
“Recording complete. Secondary analysis result: anti-barrier saturation pressure is determined to be more than fifty times and less than eighty times that of standard warheads.”
At <Iris>’s report, Eve let out an impressed sound.
Asahi, who had apparently received the data as well, sprang to her feet with a cheer.
“Ooh! Ooh! This will expand our tactical options all at once!”
And so.
<The Tree> had obtained a new weapon: the burnstone warhead.
