Last Savior

Lucas started to rush over, intending to yank old Gadget out of that terrifying cavity, when he heard the rat rasp, "D-don't touch me…" Out of breath, Gadget then added, "My… neurons are already hooked into Number Four's system… If we… forcibly separate them now… I won't last… five minutes."

"So what do we do? You planning on living the rest of your life inside this guy's belly?" Lucas blurted. "Is that even possible? Can he still move? 'Cause if not, I'll find a rope and start dragging you. We can't stay here. If that enforcer woman comes back with backup, we're dead meat!"

Gadget shook his head weakly. "Calm down… She doesn't know my backstory. For now, she won't be back."

"Okay, but what do we do now?"

"Right now?" Gadget gave a crooked smile. "Right now, I just wait for this big lug to digest me… then poop me out."

"…"

"Actually, that woman got it wrong. This isn't Number 13 at all; it's… Number Four." Gadget forced a small smile and began to describe some secret history of the Alliance. "It all goes back to the Noah laboratory. Initially, the Noah Six were not in agreement about the same research path."

He slowly went on, "When that lab was formed, the Noah Six all showed keen interest in bio-humanoid tech. But they couldn't see eye to eye on how that tech should be used. One faction believed in developing conscious bio-warriors with independent thought—a chip implanted in the brain would handle auxiliary calculations and control. That way, since the soldier could think for itself with microcomputer support, it'd be all the more lethal in combat.

"The other faction believed that bio-warriors should have zero awareness. Instead, an experienced human soldier, operating remotely, would pilot the body using neural connections. In that model, the mini-computer chip was mostly for storing data and linking the human controller's brain to the bio-soldier's neurons. The result would still be big firepower on the battlefield, but with total obedience. 

"After several arguments, they decided to produce both types and compare the data directly to see who was right."

At that, Lucas interrupted, "So this so-called 'Number Four'… is the second version you're talking about?"

The rat shrugged. "That's only the Number Four prototype we're dealing with here, not an official production model. During late-stage development, Project Four ran into an unsolvable tech problem and was shelved indefinitely."

"Oh? What sort of problem?" Lucas asked.

"Neural transmission." Gadget sighed. "They may have decoded the entire human genome, but when it comes to that so-called 'divine domain'—the human brain—they still didn't have enough understanding. The completed Number Four, while technically a bio-weapon, was actually a flesh-and-blood human with a thinking mind. They couldn't fully erase its consciousness. So if another human's consciousness entered Number Four's brain via the neural link, resistance was huge.

"I think I've got it," Lucas chimed in, suddenly excited. "Just like in all those sci-fi flicks, right? Number Four had a mind of its own and didn't wanna be controlled. So it annihilated the intruder's consciousness, turned psycho, and slaughtered the entire Noah lab—right?"

"Not exactly." Gadget's eyes clouded over. "In the end, Number Four realized it couldn't break free from humanity's shackles… and so it self-destructed."

"…"

After a moment's silence, Lucas asked again, "So if it obliterated itself, what's the story with this Number Four prototype you're operating now? How can you control it?"

"Because I, too, was an experimental subject specifically designed to interface with Number Four," Gadget said gravely, revealing his secret. "Once upon a time, my own code name was Number Fourteen."

Fifty years ago, a so-called "lucky" lab rat had been chosen as test subject #14 in the Noah group's gene experiments.

Their goal was to refine a transitional stage: before hooking a full-fledged human pilot to Number Four, they wanted to see how well a smaller test creature—this rat—could mesh with the bio-soldier. 

They implanted chunks of human DNA into the rat to boost its intelligence, which also enlarged its body dramatically. They loaded the rat's microchip with a staggering trove of knowledge to test how effectively the bio-soldier performed under extreme conditions.

Because a rat's nerves are far too thin and delicate, Number Four couldn't receive the rat's consciousness from a distance. So the scientists carved a cavity in Number Four's abdomen, creating a kind of mini "cockpit." Instead of remote control, the rat would "drive" from inside—the reason, of course, behind the gaping hole in Number Four's gut.

Once they'd gathered enough data, the researchers decided to wipe the rat's newly gained human-like consciousness, mothballed that rat-exclusive Number Four prototype, and proceeded to manufacture an official human-compatible Number Four.

But as luck would have it—for Gadget, anyway—these haughty scientists never truly figured out the workings of the human brain… nor, for that matter, the rat's. Just a couple of weeks after being discarded in a fog, the rat regained its intelligence. Yet due to the incompatibility of human and rodent DNA, whenever the rat's "mouse genes" took the helm, it would backslide into rodent behavior.

Hiding away on instinct, the rat watched the full-scale Number Four blow itself up in tragic defiance. Meanwhile, the competing line of bio-warriors advanced past every technical barrier and was eventually mass-produced as "Number 13."

But soon after, something else unexpected happened. During a live training exercise, the assembled 13s suddenly developed self-awareness. 

They turned on their human handlers in a gruesome massacre, giving rise to the Alliance's infamous "First Bio-human Riot."