The Activity sweet potato was growing with almost aggressive enthusiasm. The Research Institute immediately organized a work crew to clear twenty mu of land along the Dafangyong Reservoir bank and plant the full stock. The tubers could be sectioned into small pieces, each piece a viable planting unit — consistent watering was all that was needed. Establishment rate was high.
The sweet potato fields did something the camp had been unable to achieve through any other means: they relieved the pressure on food supply. Operating purely on daily hunting and foraging runs had a ceiling, and that ceiling was the surrounding ecology’s carrying capacity. Sooner or later, the camp would have eaten Hefei’s surroundings empty.
The Research Institute had tried to cultivate evolved fruit trees before. The seeds wouldn’t germinate — they rotted in the soil. Grafting, cuttings, transplanting: all had failed. The Activity sweet potato was the only plant the camp had successfully cultivated from human effort.
Well — the second, technically. Shen Cong still had one listless Mechanical Vine cutting on board, which was maintaining a glacially slow growth rate and contributing approximately nothing except a small patch of green in the greenhouse.
“My hypothesis is that the tuber contains an especially vital form of Activity — one that enables continuous reproduction.” Yu Fucheng, a former associate professor from Anhui Agricultural University, had been appointed director of the Sweet Potato Research Lab and was personally overseeing cultivation operations.
Shen Cong had come out to the sweet potato fields a few times over the past two days, discussing the plant’s biology with Yu Fucheng. “‘A vital form of Activity?'”
The phrasing was a little awkward, but the concept landed immediately.
His Half-Activated Armor derived from a failed metal lifeform — a form of Activity that was distinctly inert. If you thought about it that way, Activity itself existed on a spectrum of vitality. The more vital the Activity, the more vigorous the life force it expressed.
And then another thought: Is Great Vajra’s Activity unusually high-vitality? Great Vajra outperforms every other bonded vehicle in ambient Activity absorption rate and Talent ceiling — by a significant margin. Could the vitality grade of its Activity be the reason? A possible research direction.
A further spark of association. He interrupted the conversation with “Give me a moment” and went back to Great Vajra at a jog.
In the supply room, he dug through storage until he found a sealed packet.
Twenty-eight Activity Peach pits.
Every Activity fruit he’d eaten with a recoverable seed, he’d kept. The original intention was future cultivation — but after repeated plantation failures at the camp, he’d set the seeds aside and mostly forgotten about them.
The reason Yu Fucheng’s phrase had triggered the memory: Activity Peach. He’d used the “Activity” prefix for only two things he’d named himself — the Activity Peach and the Activity sweet potato. The naming hadn’t been arbitrary. Both had given him a specific sensation when consumed, a sense of something alive working through his body, different in character from other Activity fruits. He’d been chasing accuracy in nomenclature, which he considered a mark of genuine rigor.
He jogged back to the sweet potato fields with twenty-seven of the pits.
“You might want to look at these. They’re seeds from a very high-vitality Activity fruit. Worth trying to germinate.”
“Wonderful — I’ll start analysis immediately.” Yu Fucheng took the pits with evident enthusiasm.
Shen Cong kept one back. He had his own use for it: planted in the greenhouse with some evolved meat buried alongside for nutrition, positioned to receive full sunlight through the skylight. Maybe it would grow. Maybe he’d end up with a peach tree on wheels.
He settled the pit in the soil, adjusted the greenhouse shelving so both the Mechanical Vine and the new planting could access the light, and straightened up.
“The sun on my body feels so nice.”
The Mechanical Vine’s perceptual signal drifted through the link — vague, formless, the usual.
This was essentially the vine’s complete emotional range. Every day, some variation of comfortable or uncomfortable, transmitted in the same half-conscious murmur.
Shen Cong was increasingly regretting establishing the perceptual link.
It was like living with someone who sleeptalked constantly, delivering an unbroken stream of nice and not nice into the back of his awareness.
He climbed to the roof, set up the sun umbrella, arranged the reclining chair, and lay back with his face to the sky, letting his mind turn over the question that had been sitting with him.
Why does Activity have different grades of vitality? Why is some Activity ‘vital,’ some ‘more vital,’ some ‘inert’? Why is a failed metal lifeform’s Activity inert, while Activity Peaches and sweet potatoes are highly vital — and ordinary evolved beasts, evolved people, and evolved plants are simply ‘vital’ without that extra quality?
The question had no angle he could find purchase on. The answer wasn’t coming.
Nothing. Play something.
He opened his phone’s music player and let it run on shuffle.
“…made a mistake in the flower fields, said we’d forget it before dawn…”
That afternoon, the leadership convened another meeting — population policy, this time.
The Activity sweet potato had done enough for camp morale that the question could finally be seriously addressed. With food security no longer the binding constraint, reproductive planning became viable. The meeting also intended to discuss deploying iron person vehicle teams to search surrounding cities for survivors and bring them in.
Survivor search had been on the agenda since the camp’s founding — endlessly deferred because the camp could barely feed itself. That constraint was lifting.
The messenger came for Shen Cong three times. He didn’t go.
He spent the entire afternoon grinding bone-gold weapons.
Six Spike King dorsal quills, each over a meter long — enough material for six weapon sets.
Working from the cross-section and volume of each quill, he planned: one arrowhead for the hand crossbow, one javelin tip, one heavy bolt head for the roof-mounted crossbow, a batch of pellets — harvested from the tips — with the rear halves of each quill reserved.
Finished products: six Spike King Arrows, six Spike King Javelins, six Spike King Heavy Bolts, thirty-plus Spike King Pellets. A third weapon series above 1H Activity Value, joining the Ape King and Condor series.
The reserved rear sections of the six quills he planned to weld together into a retractable integrated drill assembly, to be mounted at Great Vajra’s rear undercarriage. In a pursuit scenario, with something closing from behind, deploying it unexpectedly would give any evolved beast a very unpleasant surprise.
Great Vajra’s initial overhaul was largely complete. His time now divided between precision finishing work and ongoing weapons development — continuously tightening the vehicle’s defensive and offensive systems.
What he actually most wanted to upgrade wasn’t weapons, though. It was the drivetrain.
Three uprated engines, and they still weren’t enough. Against Great Vajra’s mass and dimensions, the power-to-weight ratio remained insufficient. What he needed was something on the order of an aircraft engine.
Before the apocalypse, someone had actually done this. A Canadian engineer had assembled a jet truck from three aircraft engines — called Shockwave — producing 36,000 horsepower. Top speed exceeded 600 kilometers per hour. Zero to 400 meters in 6.5 seconds. At ignition, the two exhaust stacks on the cab roof didn’t produce smoke — they produced fire. Three jet engines at the rear, also producing fire. The whole vehicle was essentially aggression given physical form.
Give it wings and it would probably fly.
An engine system like that on Great Vajra, and nothing in the evolved beast classification system would be relevant.
The problem was obvious: no aviation engines available, no aviation fuel.
For now it remained a thought experiment.
But who said it had to stay that way? Shen Cong was genuinely looking forward to the day Great Vajra could fly.
(End of Chapter 173)