Day 31

You were bitten hours ago. The clock in your blood is already running — and it isn't a virus. Fight through the waves of the dead, trade your nerve to a demon who was here before the city, and hold onto yourself for one more wave. Turn, and it's over.

It is Day 31. A survivor reaches St. Harrow's hospital in Harrow City already bitten. The bite carries no pathogen. It leaves a mark, a countdown written into the blood that finishes on its own schedule. What sets that schedule is not biology but nerve, the old word for the force of will that keeps a person human. Those who fight last longer. Those who stand still turn fastest. Nerve is also the only currency St. Harrow's recognises. Between waves, a merchant called Vessel appears at the crossroads of the round to trade. He has never given his name, records every transaction in a ledger bound in something that is not leather, and takes nothing but nerve. Beside him sits a porcelain doll named Mara, who has never spoken and is believed among repeat customers to have been a transaction once herself. He sells weapons, ammunition, and suppressants that slow the mark for a time before wearing off and needing to be bought again. Because nerve is both the currency and the thing holding the countdown back, every purchase is the same decision made again: kill faster, or last longer. Records from the quarantine ward at Harrow General date the first observations to Day 14. The researchers who made them turned on Day 16.