Instinct

The second sun was setting in the sky, finally following its sibling beyond the western dunes. The squad had been hiking all day. They’d been out on a scouting mission when their half-track gave up the ghost, leaving them 20ks from HQ.
Still, at least they weren’t going to get wet walking home; it hadn’t
rained in the Northern Hemisphere of Kataan IV since the Great Storms, over three decades ago.

As they scrambled up the giant sandbank ahead they knew from the top they should be able to see headquarters now only one or two kilometres away. The Sergeant peaked the crest first, standing tall
in the fast dwindling amber light. Sure enough, there was HQ, bright
and shining with searchlights scouring the nearby plains.

Directly ahead at the base of the dune was a depression, approximately 500ms square. Entirely in shadow, the western dunes
blocking out the feeble glow, this was the perfect place for an ambush.
The Sergeant signalled his men to stay alert and slid softly down the
sandbank.

The ground as the base of the depression was covered in large mounds. About half a metre tall, almost completely uniform, there
must have been a hundred of them within the range of their gun lights.
It was eerily quiet. Once the suns set the desert would normally be
rife with insects and lizards, searching for food before the
temperatures dropped below freezing point, but here there was nothing.
The sun finally dropped away and took the orange highlights on the
surrounding dunes with it. Now the squad was left with nothing but
their small gun lights to see by.

The Sergeant led his squad through the darkness, picking
his way through the mounds with careful haste. By his estimate they
were halfway across when the first noise rang out. A soggy splintering,
like a wet branch snapping, followed by a heavy thud as something hit
the sand. The squad whirled, aiming their lights over the ground,
trying to locate the source of the noise. But the dune walls were
echoing the sound back and it could have come from anywhere, a hundred meters away, or from around the next mound.

The squad paused, waiting for another sound. None came and
the Sergeant moved them on once again. They’d moved on only another 20 metres when another splintering sound followed by a thud, then another.
Before they could move on the night air was filled with the same
sounds, over and over in an anonymous cacophony. The Sergeant powered up his chainsword, alerting his squad that they may need to make a stand. He took another step forward when the mound in front of him
exploded. The sand slid off, revealing a large dome made of a shiny
white substance. Pieces of this dome shattered away with the wet
cracking sound, dropping next to his feet. The dome lurched to one side and spilled its contents onto the sand with a thud. Amniotic fluid ran across the floor coming into contact with the Sergeants boot. As the liquid seeped into the ground the contact point on the boot started to steam gently.

Slowly, unsteadily, the dark form that had just appeared
began to unfold and rise up. The Sergeant lifted his lasgun up from the
ground, casting it’s light over the new form. The shape was covered in
glistening fluid, but was muscular and hard. The legs were almost
reptilian in appearance, though much longer than any native lizard of
this planet.

Time, which had been moving at a snails pace, suddenly
snapped back to reality and the scene erupted with a flurry of
activity. The Sergeants light hit the creature’s face and as
recognition dawned a spiked claw thrust straight through his stomach.
The beast roared out, provoking similar responses from it’s newly
hatched kin. As it retracted it’s claw the Sergeant watched in horror
as his intestines spilled to the floor, dissolving in the liquid
spilled from the egg. He sank to his knees and was dead before his face
hit the ground.

The rest of the squad started shouting, trying to
co-ordinate a defence before it was too late. But it already was. The
creatures, showing amazing strength and agility for newly born beasts,
leapt onto the remaining mounds surrounding the squad, hissing and
spitting at the guardsmen and each other. Half the squad dropped to
their knees, bringing their guns to bear and opened fire. They plunged
round after round into the terrifying beasts but only a single one fell
from a lucky shot to the eye.

Many of the squad were new recruits, deployed to Kataan IV
as their first mission. They had never seen Tyranid beasts in real life
before, never mind up close and personal.

Confusion reigned in their ranks as they screamed and
fired, but still the beasts just poised there, hissing. It was as if
they were vying for position with each other, wanting to establish
dominance early.

“What are they? Why won’t they die?” yelled one of the younger members as he locked another clip into his weapon.

“Hormagaunts.
They’re newly born, and separated from the Hive Mind, that’s why
they’re acting dumb. Once they figure out they’re on the same side
we’re history. Keep firing damnit,” ordered one of the older members of
the squad. He was a veteran from the early battles against the recent
Hive Fleet. He had seen what the Hormagaunts had done on Pedura XII.
He’s seen an entire company of hardened Catachan Devils fall to these
beasts. He knew they were dead already.

The beast that had killed the Sergeant reared up, screaming
above the hissing, making itself heard. All present at the scene
understood it’s intentions. It was taking control of the brood, drawing
first blood giving it first claim to leadership, at least for now.

Then it was over. The new brood leader leapt forward onto
the unwitting squad, ripping the wily veteran limb from limb,
disgorging his organs over the other guardsmen. The rest of the brood
followed suit, leaping down from the mounds, even as they hatched and
the brood’s number swelled.

In mere moments all ten members of the squad were nothing
more than dismembered limbs and blood stained sand. The beasts, hungry
to feed, set upon the corpses and those of their number still unable to
stand under their own power.

Once they finish their feast they’ll need to hunt again, driven by instinct. The instinct to kill.