Machine gun fire erupted outside. I looked around and did a head count. We were all here. Was someone else outside? Was someone shooting at us?

Ethan typed in a few commands on the small keypad. “Sentinels are running hot. Guns three and four firing on full automatic.”

“Jesus. How many are out there?” Griffin asked.

“Don’t know,” Ethan replied

“Only guns three and four?” Ramirez asked.

“Yeah. They seem to be concentrating their attack.”

The sentinels were indeed firing on full automatic, unleashing their ammunition at anything and everything that moved. According to the readout on the computer monitors, each sentinel had a capacity of one thousand bullets. The counter display was rapidly approaching zero.

We were all standing around the laptops, mesmerized by the numbers and the grainy images of the surveillance cameras mounted on the guns.

It was hard to see anything clearly, but every now and then an image of what looked like a large wolf became visible through the dust and smoke as the flash of the gunfire lit up the dark desert night.

“Targets twenty meters and closing,” Ethan said. “Guns three and four down fifty percent.”

“They’re still coming!” Ramirez shouted.

The ammo counters continued to whirl downwards to zero. The howling of the wild dogs was clearly audible. I didn’t realize it at the time but I’d put my hands over my ears to block out the sound.

“God, would you listen to that?” Griffin said. “How many are there?” he asked again.

“Too many,” Ethan said. “Gun three is dry.”

And according to the counter on the laptop, gun four was down to fifty rounds.

Thirty rounds.

Twenty.

Ten.

The gun was chewing threw ten rounds a second.

Griffin and Smitty grabbed their rifles. They were about to head out and provide covering fire. But then the firing from the remaining gun stopped abruptly. The grainy video image was a swirling wall of red dust and gun smoke. There were dark and twisted shapes, bones, and teeth and claws scattered throughout the image. But nothing was moving.

“Wait,” Ramirez said. “They’ve stopped.”

“Yeah, but look,” Griffin said as he pointed to the laptop screen. “Gun four is down to ten rounds. Gun three is empty. If they attack again, in this spot, from this direction, they’ll break right through.”

“They won’t attack the same place,” Ethan said. “They’re testing the perimeter. They haven’t attacked the same place twice yet.”

“How do you know that?”

“The last attack came from the south-west. This attack came from the north-west. They’re testing the perimeter. They’re trying to find a way in.”

“They seem to be attacking in waves,” Ramirez pointed out.

“How many do you think there are?” Smitty asked.

“Yeah, this is goddamn ridiculous,” Griffin said. “We don’t have the ammo for this.”

“We’ve still got the fence,” Ethan said. “It’s got plenty of juice running through it.”

“Yeah but what happens when the generator runs out?”

“We’ll be long gone by then.”

I swallowed hard as I remembered Daniel’s story about the target practice he used to do at the training facility. Shooting kangaroos and wild dogs and wild buffalo and wild boar. There must be millions of them out here. No one would know for sure. I tried to imagine what an infected buffalo would look like and whether or not a machine gun would be able to stop a whole herd if they charged at us. I wondered if the fence would be enough to stop something like that. Sure it was electrified, but what if they could jump it? Or charge right through? What if the wild dogs could dig underneath it?

“We better get out there and reload the sentinels before we go,” Daniel said

“Do you think it’s safe out there?” I asked. And as soon as I asked the question, as soon as the words left my mouth, I realized how stupid it was.

Of course it wasn’t safe.

But I think everyone just ignored me, chalked it up to me being a dumb civilian teenage girl, someone who had no real business being in this hostile place. I guess it was kind of funny that they needed me more than any piece of state of the art weapon or technology. Well, maybe not funny, but definitely ironic.

Ethan pressed a button on the laptop which enlarged the image from the surveillance cameras on the sentinels. He looked at the dark pictures for a while. He pressed a few buttons that flicked between infra-red and night vision.

When he switched to the night vision mode we could clearly see the aftermath. There were a frightening number of carcasses on the ground. Some of them disturbingly close.

We all held our breath as the camera slowly scanned back and forth. We were waiting, watching to see if there were any more coming. But there were none.

“Time to go,” Ethan said after a few minutes.

He said it real quietly, almost whispered it. But his voice resonated throughout the tent.