In the 200 years since humanity began manufacturing robotic droids for use in occupations deemed "sub-human," the advanced AI droids that control the factories where their later generations are produced have always made their deadlines, always kept their quotas, and never built a defective droid.

That is, until CD-4395-XI; Combat Droid, 4th Battalion, 3rd Platoon, 9th Squad, 5th Unit 11th Generation; or, as he prefers: 4395.

The dropship hovers above the war torn neighborhood in what used to be suburban Chicago. The soviet droids fell back from fear of airstrikes, but there are still civilians in the area, and must be cleared by friendly troops before the enemy returns in force.

The bay doors in the floor of the dropship open, the tubes holding the droids in place disconnect, and the artificial soldiers drop twenty feet to the cracked asphalt below. Instantly, the droids' computer chips are networked together; what one droid sees and does, the rest of his comrades are aware of. They are all programmed to work in unison, carry out complex military maneuvers and be aware of their surroundings at all time through spy satellites hundreds of miles above them; the perfect machines for killing.

All except for 4395.

Since he was powered on, he knew he was in the wrong body. While his brain told him to await orders from his civilian master and carry out duties such as doing the dishes and mowing the lawn, his left arm is an M2-82 machine gun and his right is an R-3 railgun, and his chest is made out of two inches of solid titanium armor, the same stuff used in 21st century tanks. He doesn't know why or how, but one of the factories made a mistake, miscalculated an algorithm perhaps, and now he, a service droid, is in a military body. The only question is who has his intended body?

As the dropship speeds away to collect more troops, the combat droids on the ground begin to pan out, a few taking cover behind wrecked vehicles and setting up portable artillery batteries, another squad looking through the rubble for survivors of the last attack, and several platoons dividing into smaller groups and approaching the houses lining the streets. 4395 knows that they are receiving a string of commands coordinated by the AI in a satellite, and does his best to blend it by holding his arms up the same as everyone else, walking briskly but cautiously like everybody else, and suddenly change directions whenever a new command is received like everyone else. No droid in two centuries has experienced what he is experiencing right now, and he doesn't want to discover what the consequences are.

He spots a group of droids heading towards a house, and notices that the third number stenciled on their backs is 9; his squad. He turns his direction towards them and falls in line as they march down the sidewalk. He does his best to ignore the distant chatter of machine guns and ion bombs being dropped from the city, where the war never stopped. His programming was never meant to react to an environment like this one; only calm, residential areas or the hustle and bustle of a peaceful metropolis, not the apocalyptic version of those places.

His squad turns into an alleyway, where more ruined houses lay, pieces of wood and metal still partially on fire. Member of the 9th squad in front of 4395 occasionally separate from the rest of the group as they receive commands to clear out a garage here, or a basement there. 4395 hates how combat droids don't have voice boxes like how his original body would have; he has no idea where he should be going or when, so he tests his luck and stays with the main group, which dwindles to only three of them. The droid directly in front him, 4393, occasionally glances behind him, lets his sight sensors scan 4395, and looks back forward. 4395's circuits begin to heat up out of fear of being discovered.

Suddenly, there's a blast of light, and a combat droid with the insignia of the Second Soviet Nation on his chest walks out of a newly made hole in a house directly in front of 4395. The third droid in 4395's group, 4391, fires his railgun at the enemy and takes off an arm, but the soviet machine showers 4391 with a barrage of armor piercing bullets, tearing him to shreds. 4393 crouches down and opens fire on the soviet; 4395 knows that he was supposed to have received a command to work in pair with 4393's, but he only stands frozen as his service droid mind reels, trying to find a protocol to help him in this situation.

The half-dead soviet droid charges 4393, and barrels into him just as the last of his vital circuitry is fried. The two droids are flung backwards, 4393's machine gun still firing. He must have struck a gas pipe or something, because the next thing 4395 knows, there's an explosion and he's flung through a wooden wall into a house. He quickly stands back up when his sensors don't pick up any serious damage.

The house's owner must be very wealthy; it has the design of a 21st century house, but is in perfect condition; minus the hole in the sidewall, of course. 4395 turns around, and sees 4393 prying his torso off of his trapped legs, and quickly runs into the house, certain that he's been found out.

The first room he enters is a dining room, with a long wooden table surrounded by at least a dozen chairs, and a crystal chandelier that must cost as much as him overhead. Silverware and food is still on the table, but the broken glass hints at a swift escape from the owners.

4395 slowly walks around the table. The floor to ceiling glass windows of the wall across from him are blown almost completely apart, and the wall opposite them are riddled with bullet holes. There is a pool of blood under the table, near the middle. 4395 crouches down and sees the corpse of a human police officer, blaster pistol still in hand. Bloody footprints head off into another room, perhaps the living room. He slowly follows them.

The living room is much cleaner than the dining room, the only traces of combat are a few bullets that slipped through the windows and the footprints, heading further into the house.

A firm pair of hands grab onto 4395's left arm, and he is flung across the room and into the wall, almost breaking all the way through.

"Stand down," 4395 hears. When his sight sensors clear up, he's staring straight into the barrel of a large caliber pistol, the kind designed for humans. But this one isn't held by one of flesh and bone; it's a service droid.

"Are you alone?" the droid asks. 4395 gets out of the wall and nods. This doesn't make any sense; service droids aren't programmed to handle weaponry, or speak independently outside of his listed speech options, such as "Yes, Sir," and "Task completed, Ma'am." 4395 nervously eyes the red footprints, afraid that this droid may have a corrupt chip.

"Human of this house is deceased," the service droid explains. His grip on the gun and his stance is firm, like a soldier's. "Did not obey evac protocols, got many law enforcers killed." 4395's service droid chip kicks in, and he thrusts both his arms into the air, the appropriate response for unarmed droids when facing danger. The service droid slightly lowers his gun.

"What are you doing?" he asks. "You are a CD. CDs do not surrender. I know. I should be one." 4395 can't believe his audio sensors; is this his body? He pats his chest and shakes his head.

"What?" the service droid says. 4395 points at his head, then the service droid's body. Then he points at the droid's head, then his chest.

"Is your chip a CD's?" 4395 shakes his head. The service droid lowers his weapon.

"Are you an XI?" 4395 nods. "These odds should be impossible. There are over 400,000 droids operational in the city. How did we meet so easily? No matter, I know how to fix this." The droid pulls out what looks like a computer cable.

"I'm still not exactly sure what this does, but perhaps it can link droids." 4395 nods, knowing exactly what the cable is for; service droids can use them to interact with appliances around the house. There are panels he can connect to all around the house that allows him to control everything electronic in the house. He turns to his side and points to an outlet.

"Ok," the service droid says, inserting the cable. "Hope you know how to operate it; I've already almost broke the arms of a teenager who was vandalizing my, correction, your master's vehicle. Hard enough to disguise my chip error, much less refrain from using my combat protocols." 4395 nods, and accesses the cable with his chip.

After looking through a few billion lines of binary, he finds the "souls" of him and the service droid, and swaps them. 4395's vision blacks out for a moment, and when he can see again, he is looking at a droid with the numbers "4395" stenciled on his chest. The first thing he realizes is that his name is now SD-843-XI; Service Droid, 8th Production, 4th Assembly line, 3rd Unit, 11th Generation.

The new 4395 looks down, then looks at the new 843, and nods.

"Thank you," 843 says, relieved to be able to speak out loud as his chip intended. 4395 nods again, turns to the side, and dives out the window. 843 looks out of it, and sees 4395 wrangling a large soviet droid, hammering round after round into its neck. The appropriate protocol pops into his head, and 843 rushes into the house to look for a way to contact the authorities.