Mechanical Dog & Spider

Five days. Just five days to prepare for an onslaught of millions. Zack knew he had to turn the MV-02 into a full-fledged war machine and find additional manpower. Even with its advanced armor, facing such numbers alone would be a death wish.

"Ego, pull up the data on drones and automatons," Zack commanded.

A display appeared on the screen, showing various designs: cutting-edge quadcopters, spider-like robots with four legs, and humanoid android models.

"No... these are too expensive and complicated to mass-produce quickly," Zack muttered, shaking his head. Even if he had all the materials, producing enough reactors to power them would be impossible.

"I need something simpler, something I can produce in bulk," Zack muttered to himself as an idea began to form. He moved over to his workbench, grabbed a pen, and started sketching.

Since the apocalypse, Zack's physical abilities had improved in ways he couldn't fully explain, and his mind had sharpened as well. It allowed him to tackle challenges that would have been out of reach before. Building two generations of power armor had also given him valuable knowledge and experience in mechanical design. Though he still lacked professional expertise, Ego easily filled in those gaps.

"It doesn't need to be cutting-edge, just functional," Zack thought, his pen moving quickly over the paper. "In our situation, an animal form would be more useful."

Zack's mind raced. "It doesn't even need advanced AI—just enough to tell friend from foe. A simple face recognition system should do the trick," he said to himself, pausing to write down some additional notes. "Energy will be the real challenge. Cold fusion reactors are too expensive, and graphene batteries take too long to make. Maybe something using hydrogen... it'll be easier to produce."

Two designs started to take shape on the drawing board. The first was a mechanical dog—sleek and fierce, with a long, sharp tail that could help with balance and double as a close-combat weapon. The second was a mechanical spider—a smaller, lethal version inspired by a famous RTS game from 2001, one that Zack regretted never having a true sequel. Unlike natural spiders, which have eight legs, Zack's design featured four strong limbs. The tips of the spider's legs were razor-sharp, capable of piercing even steel plates. The simpler, four-legged design saved on materials and improved balance, allowing the spider to move smoothly without the need for a complex stabilization system.

For weapons, Zack chose conventional firearms. The mechanical dog would have a more advanced AI, allowing it to patrol, recognize allies and enemies, and adjust its tactics based on its environment. The spider's AI would be simpler—it could identify targets but would rely on pre-set attack patterns.

With the final design on paper, Zack took a deep breath and, without hesitation, tore the sketches into pieces and tossed them into the wastebasket. "Ego, it's your turn now," he said, stepping back.

"Understood, sir," Ego responded.

Zack made room for his AI assistant to take over. The sound of robotic arms whirring filled the basement as the arms sprang to life. Two movable arms grabbed materials with precision, while the fixed arms, attached to the walls, picked up tools and began assembling the components. The coordination between the arms was flawless, like four skilled craftsmen working in unison, producing each piece swiftly and accurately.

"Sir, here are the blueprints for the hydrogen fuel cell," Ego announced, projecting the schematics onto a nearby screen.

Hydrogen fuel cells are compact, clean power sources that generate electricity by combining hydrogen and oxygen in a chemical reaction. This process creates electricity, heat, and water as the only byproducts, making it environmentally friendly. Hydrogen fuel cells are highly efficient and reliable, commonly used in cars, buses, and even space missions. They offer steady power and can be refueled like a gas tank, making them ideal for continuous, high-demand energy needs.

"This should be more than enough," Zack mused, suiting up in protective gear as he entered the room where radioactive materials were stored.

Meanwhile, at a massive military base in the mountains north of the capital, hundreds of thousands of survivors had gathered, clinging to one of the last safe havens after the apocalypse. They had managed to fend off multiple zombie waves and reclaim land, though resources were running low.

In the command room, images of a zombie horde in New Rochelle filled the large screen. The writhing sea of undead stretched for miles, a terrifying sight that chilled even the most battle-hardened soldiers.

"Honestly..." a voice spoke up. "We're doing well just holding our ground. It's pointless to waste ammunition anywhere else."

"Not to mention fuel," someone else added. "Flying there would burn through most of what we have left!"

"We're nearly out of food as it is," another soldier said. "Some people found out those egg-white pancakes are made from cockroaches…"

"Are we seriously considering nuking them?" came a nervous whisper.

The room fell silent, the suggestion hanging in the air like a heavy weight. Only one man, a middle-aged officer in military uniform, remained decisive. "No nuclear bombs," he declared firmly, slamming a fist on the table. "As long as there are survivors, that's not an option. We need to keep our humanity!"

Ignoring the murmurs of dissent, he stood tall, his gaze unwavering. "We'll send bombers to wipe out the zombie wave in New Rochelle," he ordered before leaving the room, his back straight.

A few remained behind, muttering, "Let him play hero if he wants. He's not the only one running this place," someone sneered.

Back in his basement, Zack worked through the night, meticulously crafting eleven hydrogen fuel cells. Each unit, no larger than the size of his palm, had a sleek, compact design, making it vastly more practical than bulkier alternatives like graphene batteries. A single unit was enough to power his mechanical dog for a full twenty years.

He examined his work with a weary but satisfied grin. "Not bad... Not bad at all."

Cradling a box of hydrogen fuel cells, Zack left the nuclear workshop and stepped into the basement, where Ego had been working tirelessly. What he saw made him gasp in surprise. Standing before him were two imposing machines: a sleek, battle-ready mechanical dog and a spider-like machine with folded limbs. Even in their powered-off state, they exuded an aura of cold menace.

"Sir, please activate the first-generation mechanical dog and spider for testing," Ego said.

Zack nodded, understanding that these were prototypes and needed thorough testing before they could be mass-produced.

He approached the mechanical dog, opened a compartment in its lower abdomen, and carefully inserted one of the hydrogen fuel cells. The dog's eyes flickered to life, glowing a soft blue—its peaceful mode. If those eyes turned red, this metal creature would transform into a lethal machine.

The mechanical dog, now powered, responded in an unexpectedly familiar way. It wagged its tail, even letting out a synthesized, eager bark as it looked at Zack, seemingly excited.

"Sit," Zack commanded, testing its obedience. Instantly, the mechanical dog settled down, responding to his every word as if it understood completely.