XCOM: Gray Dawn is a new experimental alien invasion game testing some variants of the Cyberpunk 2020 system.

Premise

A meteor shower approaches Earth out of the blue. Astronomers believe it must be a long-period orbital cloud that has not been seen in hundreds or perhaps thousands of years. Amateur sky-watchers prepare for a surprise mid-winter light show, and no one is much alarmed.

The first meteors strike, and a significant portion of London is destroyed. As the Earth rotates, the stream of meteors continues to pepper our planet's surface, sweeping from one time zone to the next. The East coast of America is hit a few hours later. Within a day, no corner of the world is left untouched.

Unbeknownst to the people of Earth, this meteor shower is not a natural phenomena. It is an alien planetary assault program unleashed in pursuit of The Mercenary that landed undetected on our planet a few days before. In his possession is the superweapon stolen from his enemies that could be their undoing. They will stop at nothing to get it back.

The Mercenary's plan, which has slowly been unfolding across the galaxy for hundreds of our years, did not take into account one important variable: Humanity. He did not--could not--know Earth was populated before he embarked on the long, slow voyage to our world across three-quarters the span of our galaxy. When he absconded with the weapon nearly a century ago, the people of Earth had just barely made it into the skies with airplanes; radio waves that could be detected by alien long-range probes would not come for many years.

Earth is The Mercenary's hot landing zone, and he realizes that he has placed this innocent civilization in great peril. He knows that his enemies would gladly destroy humanity in pursuit of him, but even worse, they would enslave us first. We are just the sort of specimen they are looking for.

The alien Collective is not the only threat, though. The Mercenary sent advance scouts to Earth several decades ago to establish bases and gather resources that would allow him to use Earth as the launch-point of his counterattack. Those bases were never built, that part of his plan failed. Certain factions have not been so ignorant of the existence of extraterrestrial life, and those ripples of influence in the shadows have created even more Byzantine agencies to hide among them.

A group of civilians find The Mercenary's hiding place on Earth, and with The Mercenary's help, they become the heart of the resistance against the Collective. X-Com: Gray Dawn is the story of this group of resistance fighters.