This is the 54 Days official trailer.
When a well-to-do Sydney party disintegrates into chaos and panic as a bomb goes off 5 friends are forced into a 1960's nuclear shelter. As food and water begins to run out they are forced to make an impossible decision - either one dies or they all die.
The Number Four in Chinese is considered unlucky as it sounds very similar to the word "death". That is why when you go to China and indeed Malaysia often lifts do not go to the level 4.
Agent 4 is a fictional biological agent that is like Hiroshima - the ultimate bomb only dirty!