They returned to their rooms and fell asleep immediately, only to be awakened by Erik's arrival well past midnight.
Under Isis's expectant gaze, Altaïr, who had initially planned to simply snack on rations, glanced at the clock. Confirming they still had some time before the agreed-upon hour, he took out his cooking utensils and fried several large cuts of meat, pairing them with high-calorie foods like cheese, honey, and buttered bread to fill both their stomachs.
After quickly assisting each other in inspecting their weapons, armor, potions, and tools, the two hunters stepped out of their quarters.
The Professor and the Elder were already waiting outside. Seeing them emerge, the Professor tilted his chin and asked, "So, how are you holding up? Combat is likely tonight. If you feel you haven't fully recovered, resting another day and acting tomorrow night is fine. These aren't empty pleasantries, don't push yourselves."
The old Wyverian's expression was utterly serious.
Isis bent her arm and patted her not particularly bulky bicep. "Full from eating, rested from sleep, I'm at peak condition! Absolutely no issues here!"
Altaïr also smiled and said, "The investigations these past two days didn't take much physical effort; it's been like resting for several days already. Any more rest and our muscles will go slack."
A flicker of amusement shone behind the thick lenses of his glasses as the Professor waved them over. "Then come along."
Led by the Elder, the group took the Lift to the top of the bedrock layer. Compared to the blistering heat waves when the Solar Furnace was active during the day, the area now felt almost chilly. The cold desert night wind was enough to dissipate the residual warmth after the Solar Furnace had been extinguished. Neatly arranged concave metal panels reflected the starlight, emitting a faint, fragmented cool glow.
At first glance, it looked less like an industrial facility for smelting metal and more like some peculiar religious site.
A few people were gathered near the Solar Furnace, including the Supervisor who had helped Altaïr during the day. They were making a series of preparations for entering the waste disposal cavern.
The preparations were actually quite simple, mainly involving procuring several long, sturdy coils of rope.
By rappelling down through the large opening at the bottom of the Solar Furnace used for discarding waste, they could easily reach the interior of the cavern. To return, they just needed to grip the rope and signal, and those above would haul them up either by manpower or with a winch.
Noticing their arrival, the Supervisor bowed his head slightly, appearing somewhat guilty. "We've learned about the situation. The last cleanup of the waste disposal cavern was over a year ago. We never expected something like this to happen..."
"Let's not dwell on that now. How are the preparations?" the Professor cut in, his impatience as evident as ever.
"Hold on a moment," the Elder gestured for the Professor to be patient.
At his signal, several craftsmen tied a thermometer to a rope and slowly lowered it down through the large waste disposal opening.
Seeing the hunters' curious looks, the Elder explained, "Although it's been over ten hours since the last batch of scrap metal was dumped, we can't be certain about the insulation conditions inside the waste disposal cavern. We're lowering the thermometer first to check the temperature inside."
The Professor nodded silently, and the hunters understood. The molten slag and metal pouring down from the Solar Furnace were all glowing red... Who knew how high the temperature below might be? If it were just thirty or forty degrees, that would be manageable, but if it were any higher, it would definitely be unsuitable to descend for combat right now.
Everyone waited quietly, and moments later, the thermometer was pulled back up.
"Forty-three degrees," the craftsman reported after glancing at the scale on the thermometer, turning to the Elder.
Before anyone else could speak, Erik slapped his palm excitedly and exclaimed, "I knew it! This temperature falls within the Vespoids' preferred range! Stimulated by such temperatures, their reproductive capacity will greatly increase. The swarm must be down there!"
The Professor gestured for Erik to be quiet, then looked at Altaïr and Isis. "The temperature is still a bit high. It's up to you to decide, but as I said before, don't push yourselves."
"No problem. Forty-something degrees is just a normal day for us Great Desert folk," Altaïr said, stretching his joints as he warmed up.
Isis nodded in agreement. "It shouldn't affect our combat ability, but just to be safe, let's drink some Cool Drinks. Better to be cautious."
"Agreed."
Craftsmen promptly handed over several Cool Drinks. For those working at the Solar Furnace, these heat-relieving potions had almost become part of their daily routine.
"Erik, take out all the Poison Smoke Bombs and Flash Pods and give them to them," the Professor instructed his student while the hunters drank their Cool Drinks.
Erik quickly grasped the Professor's meaning and clutched his pockets protectively. "W-we're not going down with them? What incredible research subjects! A Vespoid Queen mutated under human influence, along with the entire swarm!"
The Professor glared sternly at the young man. "The Vespoid Queen is a large Monster, and there's an unknown number of Vespoids in the swarm. Combined with poor lighting, unfamiliar terrain, and other disadvantages, those two will have their hands full just fighting! We'd only become a burden if we went down! Any investigation will have to wait until after they've finished the battle!"
Altaïr remained expressionless but secretly breathed a sigh of relief. Just as the Professor had said, neither he nor Isis felt particularly confident about the upcoming battle. Having to split their attention to protect scholars would only make things worse. As the expedition leader, if the Professor had insisted on going down, they wouldn't have been able to refuse. Fortunately, the old man was rational enough.
Under the Professor's firm authority, though clearly reluctant, Erik had no choice but to hand over his Poison Smoke Bombs and Flash Pods.
After stuffing these items into the two hunters' hands, the Professor continued his instructions: "Once you're down, don't rush to release the ropes or engage in combat immediately. First, assess the cave environment, check if the temperature is tolerable, if the air is breathable, and so on. The latter is especially important; air quality in such an almost completely sealed cave likely won't be great. If anything seems off, signal immediately. We'll pull you up and figure out another approach."
The two nodded seriously.
He then handed them a few more items. "These are portable oil lamps, hang them from your belts for basic lighting. And these are Disposable Earplugs to block out some noise. The Vespoid Queen is massive, and the noise from her wing vibrations when she flies is considerable. If you're too close, it could be unbearable."
Imagining the Vespoid's "buzz" sound amplified tenfold, Isis shuddered and hastily took the Disposable Earplugs to put them on. (Note)
The Professor said a few more words, but Isis just stared blankly at his moving lips.
The Professor glared at her and pointed at her ears. Only then did Isis realize and sheepishly remove the Disposable Earplugs.
"I've said all that needs to be said. Don't try to save on items, they're not worth much. If you're outmatched, retreat immediately. Understood?"
Altaïr and Isis nodded repeatedly.
The Professor waved his hand. The rope had already been lowered into the hole. With the help of the craftsmen, the two secured their sliding locks, gave a "don't worry" gesture to everyone around, and leaped into the large hole, beginning their descent.
By the light of the lamps at their waists, they could see that the passage wasn't completely vertical but slanted slightly southward, which matched some of the information they had obtained earlier.
Small amounts of slag and scrap metal were solidified on the rocky walls of the passage, reflecting dimly in the lamplight.
They descended slowly. Within just a few minutes, they had already gone down nearly two hundred meters, and the surrounding temperature was noticeably rising.
After descending another twenty or thirty meters, the passage, which had been only a few meters in diameter, rapidly expanded. This meant they had entered the cavern. The two exchanged a glance and prepared themselves.
Soon, their feet touched the ground, more accurately, they landed on the specially constructed slide for discharging slag.
Looking around, they found themselves in a sizable cavern. The portable lamps couldn't possibly illuminate its full extent.
Carefully stepping off the slide, they followed the Professor's earlier reminder and checked the temperature and air conditions.
It was hot and stuffy, their first impression of the environment inside the waste disposal cavern.
The good news was that, although uncomfortable, after a short while, both felt it wouldn't affect their combat ability.
They tugged firmly on the rope a few times, signaling "proceed as planned" to the anxiously waiting people above, then released the locks, leaving the rope end in place.
This was their escape route.
Isis naturally unfolded her great shield and Gunlance, taking the lead, her duty as a heavily armored vanguard.
Altaïr rested his hand on the hilt of his Long Sword, his eyes quickly scanning the surroundings.
Everything was silent. Suddenly, the lamplight illuminated a corner of the cavern wall, startling a Vespoid resting there. It spread its wings and flew away from the rock.
"Bzzz..."
It was like igniting a powder keg. The next moment, the buzzing of an unknown number of Vespoids taking flight merged into a deafening roar, coming from all directions.
PS. Disposable Earplugs, an item from MH4, function as the name suggests. Interestingly, in the game, the action for using them is the same as eating, somehow it feels very fitting for Isis?