Extinction Crisis: Poison Gas Spreads

An extrasolar asteroid has broken free of Jupiter's gravity and is heading for Earth.

The United Earth Federation decides to fight back with nuclear weapons. One nuclear satellite after another rises into orbit, weaving a net across the asteroid's path. After a series of bombardments, the asteroid is soon reduced to fine dust.

The victory in this battle to defend Earth is broadcast live around the world. Humanity is deeply encouraged, and people everywhere begin to celebrate.

But...

The crisis that could destroy the world has only just begun...