Dark forces are moving. Gates are opening all over the city, monsters are on the loose, and Cthulhu is starting to stir from his endless slumber. You need to close all the gates and kill all the monsters before Cthulhu wakes up and destroys everything.
This game is an attempt to make an express version of Arkham Horror. The primary game mechanic is a "Move/Effort" system, in which 2 eight-sided dice are rolled, and one is used for movement and the other for actions. Higher numbers are better for both, but be careful. Every time you roll doubles, you are one step closer to defeat.
The goal of the game is to completely remove the dark forces by closing all the gates and destroying all the monsters. Over the course of the game, various things (the biggest being rolling doubles at any time) cause the doom track to fill up. The players need to remove the dark forces before the track fills, or they all lose.