My Ledger Collects Blood Debts

In the nineteenth year of the Evernight, humanity retreated to the seventh underground level, where people survived by killing bugs for food.

Cang Yu was nineteen, a talentless nobody with worker ID C-7341. He was the least valuable kind of person at the sorting yard: shoved into a shaft as bait, he would die if the bugs came out, and die if they didn't.

All he had was a Handbook for the Life of an Evil Cultivator, pulled from the depths of a sewage ditch, and its three rules: Those who watch someone die without helping shall be executed; those who stand in my way shall feed the bugs; anyone who calls me useless will finish their last sentence on their knees.

At the bottom of the first page, another line was written in blood: Thirty days until the next settlement.

Borrow a measure of strength, pay back a measure of pain. Every transaction goes on the books, with interest accruing at one measure a day. He cut off the steward's son's hand, broke into an S-class bug nest, and traded two thousand barrels of water for two thousand one hundred IOUs, taking control of the water prices on the entire level.

Nineteen years ago, someone with the same worker ID took this handbook down Shaft Six and never came back up. The ledger's conclusion about her was just three words: Pending settlement.

She was his mother.

The thing counting at the bottom of the shaft said, "I'll come collect in twenty-one days."

He answered, "Fine. Come up and collect."

Others grew stronger through their bloodlines. He grew stronger by collecting debts. He kept track of every blood debt in this underground city.