Chapter 1

Jake Collins' fingers were shaking when he shoved the module into my hand.

I looked down.

Stamped into the metal casing on the side of the module, a row of small characters: 2025/03.

March. Last March.

Back then, how could any factory still have been running, still turning out parts?

I turned the module over, then back again.

The stamp hadn't moved. The characters hadn't changed. Every digit was clear as day.

We'd gone underground in 2023. It had been 122°F outside, the whole city dead.

But if everyone outside was dead, who had made this part?

"Look again."

He took it back and studied it, and when he looked up his throat worked. "It's from last March. I'm sure."

My hands started to go cold.

"Doesn't your department have an offline database?" I stared at the module. "Can you check the serial number?"

Jake blinked, then spun toward the terminal.

The screen lit up, casting a bone-white light across his face.

He typed in the serial number from the side of the module, one digit at a time, and hit enter.

A line of results popped up.

Manufacture date: May 2023.

Batch number: F20230517.

Inventory status: Issued.

Jake stared at the screen for three full seconds before his shoulders sagged.

He tossed the module onto the table. Metal cracked against the surface.

"The stamp's wrong."

A laugh scraped out of his throat. "Damn. We scared ourselves over nothing."

I let out half a breath of relief along with him.

A misprinted stamp wasn't exactly rare.

I picked the module back up off the table, meaning to return it to the spare-parts cabinet.

As my thumb slid over the serial number on the side, something caught under my fingertip.

I looked down. A small smear of ink-blue.

The last few digits of the serial number were blurred at the edges.

Not engraved.

Painted over.

I rubbed it with my thumb. Rubbed it again.

The ink smeared and dissolved against my dry skin.

Underneath was a different string of numbers.

Darker, finer strokes, etched precisely into the metal.

I pressed my whole palm down and scrubbed.

The ink came off completely.

"Jake." I flipped the module over, the real serial number facing him.

My voice came out dry. "Run this one instead."

He leaned in for a look, and the color visibly drained from his face.

He didn't say a word. He turned back to the keyboard.

His fingers slipped off the keys with every digit he typed.

Enter. The screen refreshed.

Blank.

He backed out, typed it again, hit enter again. Still blank.

The offline database had no record of this number.

Which meant this part really had been freshly made.

The stamp wasn't a mistake. It was real.

I gripped the module, my knuckles white against the metal casing.

"Where did you get this?" My voice had gone hoarse.

Jake looked at my fingers.

The wet, ink-blue smear still clung to them.

His lips moved twice before any sound came out.

"Diane gave it to me."

Diane.

Diane Marsh, who managed our supplies. For three years, every bite we ate and every drop we drank had passed through her hands.