Story

The world of Final Fantasy 13 is split into two very different parts. One part is a floating, mechanical city called Cocoon, which has also been described as a space colony. Cocoon is home to a few million people. These people of Cocoon are frightened of the other part of the world which is outside of the city, a place called Pulse.

Anyone who comes into contact with Pulse are believed to be part of a plot to invade Cocoon. These people are banished from the protection of the city by the holy government and their army. The people in black/blue clothes on the train in the E3 2006 trailer were being quarantined because they had come into contact with Pulse.

In the city of Cocoon, the people are protected by crystals and so can live peacefully. The crystals can create machines and living creatures. The city is even known to have been created by a Crystal.

The director of Final Fantasy 13, Motome Toriyama, has said the relationship between Cocoon and Pulse can be thought of as this: First, there was Pulse, a dangerous world where people reside under the fear of monster attack. Cocoon was made when the crystals considered what would be an appropriate living space for people forced to reside in the world of Pulse.

The crystal has chosen Lightning to bring an end to the world. When she was chosen she became an enemy of the Human Race and was believed to bring destruction to the world.

Square Enix (less info)