of the creature that’s now coming across the rocky plateau toward us. My mind tries to come up with a comparable example of terrestrial biology, and draws a blank. It somehow looks reptilian, avian, and mammalian all at the same time. I see a huge, eyeless head that slowly swings from side to side, and what seems like acres of rain-slick skin the color of eggshells. Its front limbs are much longer than its hind limbs, and joined at the center in a way that seems structurally impossible. It walks hunched over on its forelimbs, like a giant fruit bat walking on its wings. Even with its stooped posture, it’s probably fifty or sixty feet tall, and it looks like it could unfold itself to twice that height if it stood up straight on its hind legs. Its overall appearance is familiar and unsettlingly strange at the same time.
“Autocannon,” Sergeant Becker shouts. “Hose it down!”
On the opposite corner of the roof, the autocannon crew opens fire. The squad automatic weapon sounds like a giant jackhammer. It pours out three hundred rounds per minute in a slow, authoritative staccato. I watch as the rounds from the autocannon swarm out to meet the towering form coming out of the mist, and then bounce off in brilliant little explosions, sending sparks in every direction.
The alien creature lets out a piercing scream that is ear-splitting even at this distance. It sound like nothing I’ve ever heard before-a high-pitched, trilling wail that sends shivers down my spine and makes me want to find a hole to crawl into. A quarter mile away, the creature staggers and sways to one side. Then it regains its footing and continues on its path. Its sheer size makes it look like it’s moving in ponderous slow motion, but it’s covering the distance between the mist line and the terraforming station at alarming speed.
“You have got to be shitting me,” Corporal Harrison says next to us.
“Rocket launchers,” Sergeant Becker shouts from the central position. “Ready, aim, and fire on my mark.”
The autocannon is still hammering out its streams of tracers in long, steady bursts. The alien is walking right into the incoming barrage, tracers bouncing off its hide as if the creature is wearing ceramic composite armor. The Marine gunners are raking its torso, trying to probe for a weak spot, but there doesn’t seem to be one. The autocannon’s standard round is a dual-purpose shell, an armor-piercing penetrator with a piggybacked high explosive fragmentation warhead, and those rounds pack enough of a punch to take out an armored vehicle at a thousand yards. Against the tough hide of this creature, the shells burst in a shower of sparks, like oversized fireworks. The creature is clearly annoyed, screeching its earth-shaking wail, but it’s still coming at us.
Along the edge of the roof, Marines shoulder the stubby tubes of their MARS launchers, and draw a bead on the approaching creature. I only have the rifle and its low-pressure grenade launcher, which will barely reach out this far, but I open the launcher’s breech and feed it a fragmentation grenade anyway.
“In three, two, one. Fire!”
Half a dozen rocket launchers boom at the same instant, and half a dozen missiles leap out of their launcher tubes. They streak toward the alien creature, their exhaust nozzles glowing like a swarm of very large and angry fireflies. One of the missiles lands short, hitting the ground in front of the creature and throwing up a geyser of dirt and rocks. Another one streaks past the alien, missing its left side by a few feet. Then the other three warheads explode against its torso in huge fireballs that light up the night in the distance.
The simultaneous impact of three MARS rockets manages what the fire from the autocannon failed to accomplish. The alien creature is knocked off its feet. It tumbles to the muddy ground, screeching its nerve-racking scream. The Marines start shouting and cheering in triumph.
The autocannon ceases its relentless fire. I look through the optical sight of my rifle and switch to maximum magnification. The creature is flailing on the ground just three hundred yards away. There’s smoke rising from its hide where the MARS rockets slammed into it. The limbs of the alien throw up mud and dirt as it thrashes around. Then it manages to steady itself, and slowly rises back to its feet. It takes a step as if to make sure its legs are still working, and then continues its