Rook built the water purification station before anything else.
Not barracks.Not stronger walls.Not weapons.
Water.
He stood at the edge of the stream, watching it flow through the valley—clear enough to look safe, cold enough to feel clean against the skin. That was exactly why it was dangerous.
Clear water still carried sickness. Parasites. Bacteria that didn't care about levels or defenses.
Civilizations didn't fall from thirst.
They fell from disease.
Rook opened the Construction tab and selected the blueprint.
[Water Purification Station — Tier 1]
The System overlaid a compact structure beside the stream: intake channels, filtration layers, storage tanks. Simple. Efficient. Designed to run continuously with minimal oversight.
Requirements populated the list.
Stone.Metal fittings.Labor.
He got to work.
The station took longer than the cabin had. Longer than the watchtower. The System tracked dozens of small steps—alignment, pressure tolerances, flow calibration.
Each correction mattered.
[Construction Progress: 47%]
[Efficiency Check: Passed]
[EXP Gained.]
Lena helped without being asked.
She carried stone from the storage rack, tightened fittings where Rook indicated, asked questions only when something didn't make sense. She learned quickly, adapting to the rhythm of work instead of trying to impress.
By late afternoon, the blueprint locked into place.
The structure hummed softly as water diverted through layered filters, emerging into the storage basin clear and steady.
The System chimed.
[Water Purification Station Completed.]
[Potable Water Supply Established.]
[Disease Risk: Negligible.]
[Territory Stability: Increased.]
Rook opened the Territory interface.
A new line had appeared.
[Sustenance Status: Secure]
That one word mattered more than any stat increase.
Outside the valley, people were still drinking from rivers they hadn't tested. From puddles that looked harmless. From bottles refilled too many times without cleaning.
They wouldn't know something was wrong until it already was.
Rook crouched and filled a metal cup from the output pipe. He drank.
No bitterness.No aftertaste.Just cold, clean water.
Lena watched him, then filled her own cup.
"…Yeah," she said quietly. "This is different."
Rook stood and looked out across the valley.
Food growing.Water secured.Walls standing.
The First Wave was still days away.
And already, this place could outlast most of the world.
The System pulsed faintly, almost approving.
[Infrastructure Milestone Achieved.]
Rook closed the interface.
Tomorrow, he'd build housing.
But today—
Today, he made sure no one inside these walls would die from something as simple as thirst.