First op, second part.

"Now then, time to earn your pay, everyone!" Moustache, who was still refusing to introduce himself properly, said while pointing towards the tunnel entrance.

A large 7-meter opening in the wall, with a mostly smooth ground and uneven rocky walls, was what everyone was looking at. A creepy air seemed to be flowing out of the tunnel, seemingly ready to eat anything alive if it dared approach.

"The previous mining site is roughly 4 kilometers away from here. We need to go on foot until we get there and grab whatever boxes of vibranium we find. After we get those back here, we will keep digging for more. We should dig out at least 7 more tons of it as well. Split into 2 groups: one will be the pack mule group, the other will guard the pack mules. As for who gets to play mule, everyone with heavier armor. Understood?"

"Got it," came the unanimous reply. Setting off into the tunnel, the people quickly noticed that the two weaponized APC mechs stayed behind to guard the exit. Knowing they were being used as cannon fodder, they still carried on. After all, if it could promote them to being even lowly janitors at RivTech they'd still live a long and fullfilling life. 

Finding herself near the front of the ant colony, Uria kept occasionally looking around the tunnels that kept appearing on the sides. Most of the tunnels were collapsed, some intentionally, some by nature, with rubble completely blocking one from passing through them. The occasional rare tunnel that wasn't collapsed had traces of people going in and out of there, with occasional monster tracks or bloodstains scattered about. As they kept descending deeper and deeper, she kept using her Tremorsense occasionally to check for ambushes.

Soon she wasn't disappointed and picked up the skittering that Stalkers make, many tiny vibrations in a repeated pattern, courtesy of their form of locomotion. She wasn't the only one, however, as the person with the armor at the very front raised his gun and said, "Stalkers ahead, their number... " 

"14." came the reply from one of the RivTech guys. 

While getting ready, everyone waited for the critters to get closer to show off to RivTech. Uria, with her 2-meter-long staff ready to swing, noticed them getting closer and closer. Yet she was thoroughly disappointed. As soon as all the Stalkers were in the line of fire, one of the black armors at the back raised its gatling laser and unleashed a blue storm of violence and fury upon them. After he stopped firing, with merely a second having passed, only bits and pieces of the creatures' bodies fell to the floor, and the rocks at the ceiling were glowing red with countless tiny holes bored into them.

"Job's done," he replied.

If one could now look into the head of every non-RivTech person there, they would only see a wall of text that said, "I NEED IT!" 

After everyone woke up from their stupor, they decided they would try their hardest on this mission. Advancing further down the tunnel, they had occasional encounters with Stalkers, yet those were turned into sieves by the people at the back casually pointing in their general direction and firing. Without any hiccups, they arrived at the original point and found it completely empty.

The boxes that should be filled with ore to the brim were empty. The rocks were also completely missing, not just spilled out from them. 

There was no promised vibranium, and after Moustache checked everything by turning even the tiniest of rocks around, he started shouting furiously at the air.

"WHO, WHO IS IT?! WHO HAS THE GUTS TO STEAL THE DAMNED ORE FROM MY RIVTECH, UNDER MY NOSE TO BOOT. SHOW YOURSELF AND I PROMISE I WON'T EAT YOUR LIVER, YOU DISG—" Yet his shouting was interrupted by high-pitched screeching.

"Kieeeek!" From one of the mining tunnels appeared a silver-colored quadruped. At the forefront, a pair of powerful legs used for crushing and digging through rocks stood out. Other than that, a jaw filled with neatly organized shining teeth, that could be used to star in toothpaste commercials, was one of its main defining features. Another thing you could notice was the apparent lack of eyes on its head; it seemed to be using sound and its tongue to find its way.

Seeing the 3-meter critter, the RivTech squad was ready to open fire on it and, like the others, turn it into a sieve. Yet Moustache shouted, "DON'T SHOOT IT, I REPEAT, DON'T SHOOT IT. THAT'S A TERRAVORE. WE CAN GET BACK EVERYTHING AND MORE IF WE CLOBBER IT TO DEATH. GO, MY GRUNTS! QUICKLY!"

A few moments after he said that, everyone charged at it with their melee weapons in hand. Seeing that it didn't intimidate anyone and that they charged at it, the creature turned tail to run away.

 Closest to it at the beginning and first to arrive next to it, seeing that it was about to try running, Uria grabbed its hind leg. Noticing that someone got hold of it, it gave up running and started turning around to bite the attacker. Yet as it tried that, she started pulling back her armor with all the strength she could muster. Just as the terravore felt its body get lifted off the ground, it managed to turn around. Yet she was prepared. With the leg in her right hand and her left one holding the staff, she swung the staff full force towards its head.

"CRACK!" Seeing the terravore firmly biting down on her staff, and it being deformed by its bite force, annoyed her. It wasn't even injured to boot! 

Changing her plans, she instead did an overhead throw, sending it flying for a dozen meters. And as all things that go up need to come down, it crashed down. Shaking its head from the previous impact and dropping the staff from its mouth, it then realized a grave problem.

It was in the middle of a pack of wolves. As the wolves charged it, a lonesome scream of terror was let out by it. After a minute of everyone hired for the task performing extensive "plastic surgery" on it using melee weapons, it finally fell quiet for good.

Approaching the terribly bruised corpse and inspecting it quickly, Moustache gave everyone an OK sign and explained with a smile on his face, "Great, this is great. Usually, we need to treat vibranium for our weapons, and that costs a lot of time and money. With this thing having eaten the vibranium and having purified it, it added it to its armor. Meaning, we can simply rip it off! Marvelous. SIMPLY MARVELOUS! The reward is increased by 25 creds for everyone, minimum! And you who threw that thing, extra 30!"

Hearing that, everyone cheered. A 15-cred increase is by no means small, as that's worth a low-grade mission! Uria also felt her mood improve, even if she didn't get to use the system she was given a creds bonus. Maybe she could afford herself a decent weapon.

Telling two of the RivTech armors to carry the corpse back to the surface, leaving only one behind, Moustache decided to keep going with the mining operation. Suddenly, his watch rang, and after answering the call in private, he had a serious expression on his face. After thinking for a moment, he started climbing the mech. Once he climbed up above everyone, he shouted, "How many of you know 'harden'? Raise your hands."

Seeing 17 hands raise up, he nodded then continued, "I got news a Stalker swarm is approaching from down the main tunnel. While it's not guaranteed they'd crash our party here, I don't want to risk all of us getting eaten. You will directly help with mining vibranium from now on. One hour later, we're heading out. And conserve some energy. The vibranium veins are silvery in color, and you just need to punch them while under harden so you don't screw up your armor. It doesn't matter if you make a mistake and don't get the right thing, either. Drop what you get in front of the mining mech since it can filter what's valuable or not. "

Getting to this point, he paused and said,

"Everything you get, as long as its valuable, will be bought at 70% by RivTech. Any questions?" 

After a moment of silence one of the less experienced people asked, "Why not at 100?"

Moustache, unbothered, replied "Who owns the tunnel? And who pays monthly for it? 70% is pretty generous, it's almost us being at a loss. Almost." 

Realizing that they got the opportunity to make a killing if they got lucky by mining inside of a privately owned mine, everyone got fired up. 

Seeing that no more questions were asked, he said,"Now then, pick a tunnel and go!"

Having already completed other missions, they dispersed instantly after hearing what trouble was coming. A swarm of stalkers! More than a thousand of them! While it was unlikely they would die, they could still go bankrupt if they have to repair their armor. No way! Replacing a piece of armor can cost anywhere from a cred to dozens of creds per armor plate. It was a black hole that could burn through your wallet if you aren't careful or loaded.

There was also the chanve of finding rare materials that could earn one dozens if not hundreds of creds, as well. 

Having picked a tunnel, Uria advanced while setting up a timer. After a few forks in the deep tunnel, she didn't feel the presence of anyone else using her Tremorsense. Occasionally seeing different veins, she used her watch to identify what was what. Mostly bauxite, occasionally pyrite, occasionally quartz. All worthless.

Having spent 30 minutes like that, she was starting to get impatient. Pulling back her fist and throwing a simple jab at the wall, she hardened her armor's fist as it punched into the rocks. Seeing the rocks crack and that there was a whole lot more rock behind it, she kept punching. Seeing the meter-large hole in the wall, she carefully inspected it and saw that it contained... more normal rocks.

Giving up on this spot, she kept going to a few different ones down the tunnel. In the end, she only managed to find... a lot of rock. And a small green geode. Slightly disappointed and with the geode in her hand, she returned back to the original area and was at a loss for words. Seeing the scene of every mech carrying a mountain of rocks in their hands of different colors and that everything was sorted quickly by the mining mech into useless and useful. In the end, it was some guy who managed to find a luxury gemstone that struck a jackpot at 100~ credits in value. 

Needless to say, the gemstone was bought at 70% of the valued price, as was agreed on before. Yet he was still smiling from ear to ear, knowing he made a fortune. 

The geode she had picked up was a rare form of titanite, that while it did have a different rare material in it, wasn't worth more than 20 creds total. 

Having sorted everything valuable, the mech picked it up and stored it inside the pockets on its legs, arms, and in it's metallic backpack. Seeing that all 20 people were back and that only 55 minutes had passed, Moustache ordered everyone to retreat in an orderly fashion. While it was only a 3-hour adventure for him, he was happy to be running away from here. Plus, he got a bunch of purified vibranium, so he was satisfied. What awaited them was hopefully an uneventful return journey.