"I think it needs just a couple more minutes," Wilson said without taking his eyes off the machine. He was staring at a clear plastic cover which extended from the front of the machine to its top. Dennis walked up beside him and peered inside the machine. A printhead was moving back and forth on two perpendicular metal arms, sweeping across the build area. Occasionally the head would jump from spot to spot.

Dennis turned and looked at Wilson's computer. There on the screen was a CAD image of a gun. He looked back inside the machine and shook his head, smiling. "I still find it amazing you can do such things."

"It's a whole new ballgame," said Wilson. Just then the printhead made a final sweep over the build tray and slid back to one corner. The noise stopped.

Wilson raised the clear plastic cover, reached in, and picked up a piece of black plastic. He turned it over in his hands. He gripped the handle and slid his index finger over the trigger. "Perfect." He held his arm straight out and pointed the gun towards the far wall. "This is it."

"You're going to shoot it?" Dennis looked at the gun. "It's fully functional?"

"That's right," said Wilson with a slight grin of satisfaction. "The printer I got handles a brand new photopolymer which increases the strength of the resulting material to a point equalling metal. There is a lot of pressure in a gun during a weapon discharge and plastics don't handle that too well. While people have been fabricating auxiliary parts from plastics, it has been customary to use steel for the barrel and firing chamber." Wilson gestured to the gun in his hand. "There. You have before you a gun which has been completely printed; everything. Instead of printing parts and assembling them, you can now print the entire gun in one crack."

Wilson pressed the release and pulled out the magazine. "Look at this. Even the spring inside has been printed."

Dennis took the piece and held it close to one eye. "Wow. I had no idea this 3D print technology had gotten so sophisticated." He stuck the end of his index finger in the open end of the magazine and pushed against the spring-loaded piece several times.

Nodding, Wilson patted the machine. "I've been saving my pay for this baby and I'd say it's been worth the wait. The prices have come down considerably and with the arrival of some of these new materials, there’s a lot of interesting things you can do." Wilson pointed to a group of cartridges laid out beside the machine. "I have polymers for metal, glass, and rubber, with various options for transparency and color. I even have materials that conduct electricity so I can make electrical devices. I’m looking forward to seeing just what this machine is capable of."

Wilson paused and looked at his friend. "So? Did you get what I asked for?"

"Oh yeah, sure," Dennis said, handing back the magazine. "Although I tell you it wasn't that easy. If you’d asked me for some drugs it wouldn't have been so difficult." He chuckled. "Fortunately, I knew a guy who knew a guy and I managed to pick up a dozen for free." Dennis dug around in his pocket. "I told him what you were doing and he was very much interested in knowing what the outcome would be." Dennis put a handful of bullets down on the table.

"Don't tell everybody. This is supposed to be a secret." Wilson put down the gun and picked up a bullet. "I'm sure Dad would be really pissed if he knew I was doing this." He examined the magazine and turned the bullet over in his fingers, aligning it with the top. Pushing down with his fingers, he depressed the bullet against the spring-loaded follower.

Dennis stared at his friend, fascinated by the process. He had never seen a gun up close, never mind shot one.

"How many bullets does it hold?"

"The specs said ten," said Wilson. "This model is supposedly based on the Glock. That's why I asked for nine millimeter bullets." He carefully added each bullet, one after another, until the magazine was full. "There. That should do it. And I see we have three left over. It seems you got a baker's dozen."

"What?"

"Never mind," said Wilson. "Why don't we go out back into the woods?"

"Aren't you worried the neighbors will hear this?"

"First of all, we're a bit of a way from the next houses. Secondly, if we walk back far enough, there's a rise in the land. If we go up and over, on the other side, we'll be sheltered from the neighborhood. I'm sure any noise we make will be blocked by the hill."

Dennis grinned. "All right, let's go. I'm kind of excited about this. I’ve never fired a gun before."

Wilson chuckled. "Okay, hold your horses. Let me do a pit stop and lock up here, then we'll head out back." He put the gun down and walked out of the room. Dennis picked it up and turned it over in his hand. Wow, this was wild. You could make a gun right in your own home. Who knew what would be next? This was very much the realm of science fiction. Okay, it wasn't quite the replicator from Star Trek, but it did show the potential for this type of technology.

Dennis heard a toilet flush. He picked up the magazine and stared at the bullets. Turning the gun to one side, he gently tried to slip the one end of the magazine into the handle of the gun. It wouldn't fit. He held the end of the magazine up and looked at it, then peeked inside the handle. There were several grooves. He looked at the magazine and saw some ridges. Dennis furrowed his brow as he realised he had to turn the magazine around to get it into the handle.

Wilson walked back into the room. "Ready?"

"Sure. Do you know how to get the magazine back in the handle?"

"I guess." Wilson took the gun and the magazine from Dennis. He poked the magazine in the handle, felt it resist, then turned it around and easily slid it into place. "There, easy as pie."

"Are you sure that's right?"

"Hey, what do I know about guns? I got the design file from the Internet. I'm sure the author knows what he's doing." Wilson started towards the back door and waved at Dennis to follow. "Come on. Let's give this baby a test fire and see what she can do."

The two boys headed across the back lawn and followed a path into the woods. Fifteen minutes of winding path found them on the other side of a small hill in a clearing.

"What are you going to shoot at?" Dennis asked, looking around.

Wilson pointed. "Why don't we try that tree by the rock? The land rises behind it so if we miss, the bullet won't go flying off to God-knows-where." He raised the gun and held it with both hands. "Now keep your eye on the tree."

Dennis stood beside Wilson, a couple paces away. He looked towards the tree and held his breath. He briefly glanced at his friend and saw him holding the gun steadily as he shut one eye and squinted with the other one, trying to aim.

There was a sharp bang.

Dennis stared at the tree but didn't see anything. He didn't see anything hit behind the tree, either. Was the bullet so small he wouldn't be able to see where it had lodged?

Dennis heard a muffled noise and turned quickly. Wilson had fallen down. He was crumbled up on the ground as if he’d fallen backwards.

"Wilson?"

His friend didn't move. Dennis took two steps closer. There was a red mark below Wilson's right eye, just beside his nose.

"Wilson?"

Dennis got closer and leaned over. Wilson didn't seem to be breathing. Dennis looked down at the gun. The back part of the gun looked as if it had exploded outward. Had it malfunctioned? What had happened?

"Wilson? Hey, are you okay?" Dennis looked at his friend. Jesus, was he dead?

Dennis took out his cellphone and dialed 9-1-1.

###

Officer Haldiman sat back in his chair, holding up the gun. He turned it around several times, carefully examining it from all angles. He laid it out in the flat of his hand to weigh it, then grasped it in a shooting grip.

"Hey, Fred. Is that the weapon?" Another man dressed in a suit and tie had crossed the open area between the desks and stopped beside the detective.

"Yep," said Fred. "This is it, George. This is what killed the boy; all fabricated in his own home using a 3D printer he himself saved up for."

George nodded. "It's a different world."

"You're telling me. It's not enough we have to deal with new technologies introducing new weapons, we also have new technologies introducing new ways to cause harm."

"New ways to harm?"

Fred looked up at George and held up the gun. "This has been booby-trapped."

George looked at the gun and furrowed his brow. "How?"

Fred reached over to his desk and held up a page containing a diagram. "Whoever posted this spec file modified the original file to create a gun that shoots backwards to the shooter."

George reached out and motioned to Fred to give him the gun. He began to turn the pistol over in his hands, trying to discern what Fred was talking about. He stopped and looked at the back end of the gun, which had exploded outwards.

"The magazine was made to go in the wrong way. The bullets point backwards instead of forwards. The entire firing mechanism has been turned around so the firing pin shoots out towards the back of the gun, firing the bullet straight back to the person holding the gun."

"Why would somebody do such a thing?"

"Beats me. Terrorism? A vendetta against the world? Somebody, I don't remember who, called this a type of malware."

"Malware?"

"Yeah," said Fred. "Except instead of the intended target being a computer, the intended target is the user himself. I would call this 'killware'. Many viruses are released into the world not for profit or gain, but to just simply see if it's possible to do it. There could be a very good chance that whoever did this just wanted to see if it could be done. In the same way the author of a virus rationalizes his actions by saying that it's the user's fault for being stupid enough to click and infect their machine, the author of this modification could be saying it's the fault of a stupid user who fires the gun. Kill yourself? Tough beans; you're the gullible idiot trusting things you download from the Internet."

"That's pretty cold."

"Yes, it is. But go figure our capacity to do evil. With the Internet, you're not even dealing with real human beings. You’re completely divorced from the consequences of your actions. It's a video game. Caveat emptor. Buyer beware."

"Do we need to educate the public?"

Fred looked reflective. "That could prove problematic. This gun is one complete unit. You can't take it apart. You can't break it down and study it as it was designed electronically and manufactured basically as one piece. If it breaks or wears out, just make another. Heck, if it gets dirty and needs cleaning, throw it out and make another. Is your average user going to be able to decipher the design file to know what's inside?"

"Well, I would think..." George's voice trailed off.

Fred glanced up at him. "Think about it, George. You and I download stuff from the Internet onto our computer. Do you know what you've got? I don't. I'm not a programmer who could go through the code and figure out if the stuff is malicious or not. Like everybody else, I'm relying on downloading from trusted sources with the idea that the thing I've got is perfectly safe. But is it?"

"You're painting a pretty bleak picture."

Fred shrugged. "Every new development has a bright side and a dark side. Let's just hope the bright side outweighs the dark. And we’re not one of those unlucky few who end up in the dark. Permanently."

###

Anark666 logged into UAN, the Underground Anonymity Network, and bounced his signal across multiple servers before checking his public postings under the name “Handyman”. He noted that his AMF spec file for the modified 3D Glock 17 had been downloaded twenty-eight times. Out of curiosity, he went to Google News and typed in 3D Glock. He got back several hundred entries. He scanned down the list on the first page of results, then clicked to the second and third pages. They all seemed to be the usual newspaper articles discussing 3D printing, explanations of printing guns, and the legalities of using this new technology for creating something lethal. One journalist had titled his piece, "Guns don't kill people, printers do."

Finally on the fourth page of links, he saw an entry from the Newmarket Times Review with the headline "Local boy killed by 3D gun." He opened the page and began scanning the news story. "Wilson Rutledge, 18, was killed this past Sunday by a gun created with a 3D printer. Police said that the design file downloaded from the Internet contained a sabotaged version of a Glock pistol."

Anark666 nodded periodically as he finished reading the article. He rubbed his chin thoughtfully as he mulled over the story, then chuckled a bit. "What an idiot." He shut his browser and opened his CAD system. The day before, he’d downloaded the design file for a desk lamp, a modern-looking metal and glass design. It actually looked quite sharp. And now, with a few minor changes to the specifications, he was going to directly connect the inner workings of the light socket to the metallic exterior of the lamp. When somebody touched the base to turn on the light, they would be touching the full voltage of a wall plug. Wouldn't that be a shocking surprise? Anark666 smiled.