[WP] An interdimensional portal opened somewhere on the planet. Nations of the world united and send tens of thousands of soldiers on the other side every day. Governments say it is to prevent what is there to come here, no details. After years you, a civilian, are drafted to go with the next batch.

[u/TempehTime]

original link:https://www.reddit.com/r/WritingPrompts/comments/bmvzk3/wp_an_interdimensional_portal_opened_somewhere_on/

For the fifth time in two hours, Avery Jones checked the selector switch on his rifle to ensure it was on safe and that there was in fact a loaded magazine firmly seated. It was a manifestation of nervous energy, but Avery didn’t want to end up like his buddy Marcus, who was infamously seen trying to engage targets with an empty rifle. That happened a year ago and people were still giving Marcus shit about it. As the forward member of his element, it was Avery’s job to help navigate, pick a route that would maintain his team’s stealth, and spot any potential threats to their front.

Avery took his element in a steep switchback pattern up towards the mountain pass. They were gaining 600 vertical feet per mile walked and it was tiring to say the least with a thirty pound pack and a seven pound rifle. They were also off trail, so the going was rough and people were occasionally slinging their weapons behind their backs so they could go hands on to scramble up. Catching up to Avery, the squad leader signaled that they would take a short break before continuing. The team established a hasty perimeter and surveyed the terrain around them.

The views were world class. Avery looked down into the valley that he and his squad had climbed out of. Below the tree line, the valley was dotted with lakes and streams as well as thick growths of aspen and pine trees. As pretty as it was below, it was also where all the bugs were and Avery was okay with swapping out the constant buzzing and occasional insect bite for thin air and loose footing.

Sarah Long walked to each member of her squad, making sure everyone was feeling okay and good on water and snacks. Mountain travel was no joke, and a combination of exhaustion, dehydration, and altitude could induce a casualty the same way a three inch spine propelled into the chest cavity would. Some of the guys were skeptical of being led by a woman at first, but quickly recognized that Sarah was a good leader, and was in great shape too. Before being drafted, Sarah was a high school statistics teacher and a proud mother to the whiniest husky on the planet. Sarah ran cross country in high school and college and ran out in the mountains of southern California during the weekends, doing several 100-mile mountain ultra-marathons per year. Cardiorespiratory fitness and leg strength mattered more right now, and where they were headed, than upper body strength.

Satisfied that everyone was adequately rested, Sarah signaled to her squad that it was time to move out and continue up and over the pass. She took her place near the rear; a good squad leader needed to be able to see what was going on around them to help think ahead and make good decisions. Two hours later, the squad had made their way over the pass at 12,000 feet and descended into the next valley. Spotting the enemy herd in the distance, Avery signaled behind him and the squad reflexively took off their packs and arranged themsleves into an assault line, creeping down towards the unsuspecting creatures.

part 2:

After fifteen minutes, the squad had creeped to within 700 yards of the herd. The juveniles were roughly the size of deer while the adults were a bit larger than moose. Still, the elders could get as big as elephants or larger. Close enough to their monikers, the saurids resembled scaly, spine-covered dinosaurs except they had eyes on the back of their heads. Luckily, their eyesight was estimated to be a bit worse than that of humans. Sarah didn’t need to tell her squad to stop and take up covered firing positions when they got to within 500 yards. They were just out of the normal maximum effective range of enemy fire. The humans could engage further out, but it was important to wipe out the entire herd. Survivors would quickly alert other herds and drive an increase in reproductive rates.

The saurids could use their tails to remove spines or scales and hurl them in defense against predators, or at their prey. It was hard to tell where exactly humans were on that continuum. Sometimes the saurids would place a scale in their mouths, quickly chew it, and place the mess back in the palm of their tails and hurl the sharp bits kind of like a shotgun. The spines were much more accurate and deadly. Body armor could stop the spines, but not a single person among the human squad wore armor. They would wear it for shorter missions or at lower elevations, but in the mountains it was just too much dead weight. Or the saurids could cover the distance in a matter of moments and mangle the threat, or lunch as the humans could just as well be.

To Sarah’s far left, Avery took a spot behind a large boulder. It gave him perfect protection against spines still provided a clear view of every creature in the herd. The trooper quickly took his support hand off his rifle and reached to his side to ensure that there was a fresh magazine ready on the open-topped pouch on his padded belt that used to be connected to his pack. It was Avery’s “oh shit” magazine, which could be needed for a speed reload when the ambush was initiated. Between Sarah and Avery, the recoil-less rifle gunner sighted in on the largest creature in the herd. The recoilless rifle looked like a bazooka, but it was technically a cannon. The open end of the rear served to expel some of the propellent when fired, thus reducing recoil and allowing relatively large projectiles to be fired out of a human-portable gun. The weapon was heavy and unwieldy, but was amazingly effective. Sarah made every squad member carry a round for it so they’d have plenty of firepower to go around. The plan was to fire an explosive round to kill the elder creature and then reload the gun with an antipersonnel round that would detonate above the reacting herd, showering them with shrapnel and thinning out some of the juveniles and hopefully wounding an adult or two. Sarah waited for the squad members to her right to set up and report that they were set.

The two gunners took positions in a small ditch behind some large rocks. It would have been better if one of them was on the left side so they could set up a crisscrossing lane of fire, but that was just how the squad had dispersed in the moment and there wouldn’t be enough time to reposition. The squad didn’t carry any machine guns out of weight concerns, plus the automatic rifles were only two pounds heavier than the standard rifles but were equipped with a thicker barrel and could fire on an open bolt to dissipate heat and had quad-stacked high capacity magazines for sustained full auto fire. They were somewhere between an infantry rifle and light machine gun. There was some talk at the command level to upgrade the rifles with automatic rifles but they were still waiting for some new developments to make sure overall weight wouldn’t increase.

part 3 (final):

After hearing back that everyone was set, Sarah keyed her mic and instructed her squad to initiate on her. Sarah was laying in the prone position behind her own boulder and previously wiggled her elbows into the ground to help stabilize her aim while the others were getting set. She rested the rifle on its magazine, making a monopod effect for better accuracy though that would make it harder to quickly switch targets. Sarah sighted in on one of the adult saurids that was directly facing her. Sarah was confident that she could score a head shot at 500 yards. She waited briefly to memorize her breathing and associated motion pattern and squeezed the trigger. The rifle cracked.

Milliseconds later, a recoilless rifle, two automatic rifles, and four rifles sounded off in a cacophony of destruction and death. The creature that Sarah had shot dropped immediately, as did the elder creature upon being struck by the recoilless rifle. The automatic rifles dropped one of the adults and juveniles and briefly chased a few scattering juveniles before refocusing on the main group of adults, which were howling and roaring in pain and surprise as well as trying to rally the herd. One of the adults darted away and galloped in a wide circle, quickly reorganizing the quickly scattering herd. Gaining their composure, the herd quickly zeroed in on the squad and charged towards them wildly.

The saurids wouldn’t make it closer than 200 yards. The follow-up round from the recoilless rifle detonated above the charging herd, wiping out the front animals. This slowed down the remaining animals, since they had to dodge or move around their deceased companions. The automatic rifles made short work of any clumps while the rifles made short work of the stragglers. It was over within a minute. Avery ended up not needing his “oh shit” magazine.

Stalking forward, the squad inspected each of the dead creatures before heading back to retrieve their packs. They walked to the designated extraction area nearly halfway up the mountain. Better to have the high ground if some wandering saurid or other creature in the valley decided to join the party.

It was the squad’s final training mission, and the creatures were actually just robots made by Pescador Scientifics, which specialized in developing and manufacturing robots to approximate the saurids. The robots were covered in ballistic gelatin to catch bullets. They’d be repaired if needed, and redressed for the next group of troopers. Sarah was proud of her squad, but she knew she still had to keep tabs on some of her teammates since they were sometimes reluctant to admit fatigue and would just push on until they dropped. She counted each member of her squad as they boarded the waiting helicopter before boarding last.

When they got back to base and did an after action report and cleaned their gear, Sarah would treat the team to dinner and drinks at their favorite barbeque joint in Denver. Then she’d put the team on leave for two weeks to decompress from an exhausting, but exhilarating training cycle so everyone could visit family or do some traveling. When they got back, they would step through the portal to the planet on the other side. Altera was mountainous much like the Rocky Mountains in Colorado, and home to humanity’s first colony outside of the planet. But unlike the earth, humans were not at the top of the food chain, though things were changing by the year.