From the Game's Introduction:
This is a horror game for two players. You should play at a table, somewhere quiet, where you can turn the lights low enough to still read and write, but just barely. Both players should know that they are in the midst of some kind of widespread attack of hysteria and violence. It must be a disease, a disease that causes normal people to go mad and kill, without hesitation and without mercy. Worse, it causes those that are murdered to rise again and continue to kill. The cycle of killing and reanimation has gone on for days and days, and in those days, the two of you have found a safe haven here, in this room. You sit quietly, listening to the screams outside. You know that these people, the infected, these... things, they are attracted to noise and movement, so you wait, patiently hoping to ride out the storm. Surviving, but for how long?
At the start of the game, the players write down on cards the names of six people that they both know and care about. Each round (spaced out by silently counting a minute between rounds) one card is drawn, as the players hear that person banging on the door.
The players each flip a coin and place it under the card, with the player that drew the card able to look at the coin, but the other player's coin remains a secret. If both coins show heads, the person is alive; otherwise they have already become a ravenous zombie.
The characters have a gun with one bullet. Letting in a zombie will kill them both if they have no more bullets.
Play continues, with the players debating who should be let in, until all six rounds have played out, or either player dies.