Platform 84

After Earth and its resources were used up, the human race moved underground, building 100 Platforms stretching down into the Earth's core. 87 years later, the people of Earth were still surviving, thriving even. Platform 1 housed Earth's prisoners and social outcasts, as Platform 100 housed the social elite. Each of the platforms comes under threat when a masked terrorist surfaces. It's up to a few people from all across the platforms to stop it, and if they can't, everything they know may come to an end.