Shadows of a Twilight City
On earth, in the year 2036, a gang of terrorists were discovered. They were threatening to detonate a bomb that would wipe out the entire Northern Hemisphere. Two of the world's best secret agents, Michael and Gina Cherome, were sent to stop them.
The group was successfully disbanded, but during the final fight with the gang leader, an old experiment was unearthed. What with global warming and nuclear wars and such, there were plans to Terre form Mars. A biological bomb, for want of a better word, was set off that covered the entire world with a dense, thick forest, populated by strange, unknown plant species and odd types of animals that would eat you, rend you limb from limb, just for amusement.
Only a few central cities, like Canberra, California, Moscow, Tokyo, London and Delhi, remained unscathed. Every country excavated underground, creating it's own giant cave city. America ended up getting a large structure known as Emerald City.
Ten years later, Michael and Gina's children are six of the most famous people in emerald City. A writer, a director, a pair of comedians, an artist, and a mechanic. They befriend a fashion designer and an actor, and set off on their adventures.