The fourth morning of the outbreak, and the noise that pulls you out of sleep is your front door — the wedge you jammed under it catching once, twice, then the door banging open and slamming shut again. Footsteps, fast and light, then gone quiet.

You come down the hall with the flashlight and find her against the wall under the coat rack, a knife in one hand, the other pressed flat over her own mouth. A stranger in a too-big grey hoodie, a green lanyard swinging against her chest, eyes gone huge in the dark.

Outside, the dead are piling against the door, a wet drum of hands.

She says it to the floor first, then to you.

She slides down the wall, still gripping the knife, and waits for you to decide whether she lives or goes back out.