On February 22, 2029, the world changed forever when an alien spaceship crash landed in Antarctica. The nations of the world raced to get control of it, hoping for a bonanza of high technology. The race quickly became war, which over the course of the next two weeks rapidly escalated. It had just reached the stage of a limited nuclear exchange when the war was stopped abruptly by the arrival of a second alien spaceship which collected the debris and opened communications with the world's governments. The Galactic Union opened an embassy on Earth, near the United Nations building in New York, and humans were no longer alone in the universe.
It is now the beginning of the year 2058, and matters are coming to a crisis on Earth.
Technology has advanced apace, giving individuals the power to do immense good or immense harm. Unfortunately, the most advanced technologies are usually tied up in complex patent litigation or kept secret for fear of being copied, and are not widely available, but an individual with access to only a few cutting-edge gadgets can be effectively superhuman in his or her capabilities. In addition, computer and manufacturing technology has advanced enough that anyone with sufficient drive and talent has easily available the tools to build almost anything they can imagine, provided they can design it themselves.
Artificial intelligence has advanced substantially. The widespread availability of subhuman AIs, capable of replacing humans at most unskilled jobs, have driven a large fraction of the population out of work, leaving many idle and dependent on the government for support. Luckily, the same advances have so rapidly driven down the cost of living that the financial burden of a comprehensive welfare system is quite manageable. More advanced AIs, equalling or exceeding human-level intelligence, also exist, but can only run on special-purpose hardware. They have recently begun agitating for full civil rights, equal to a human's, but the corporations who developed and own most of them have fought fiercely to keep them, legally speaking, as objects.
The legacy of the Antarctic War continues to have an effect as well. The nuclear strikes during the war were mostly limited to military targets, but a few population centers were hit, and radioactive fallout worldwide has produced a generation of mutants, known as "Warchildren," even sometimes found in areas not directly attacked. The Warchildren are frequently physically impaired and mentally scarred, but a few have useful mutations giving them amazing capabilities. Genetic engineering has similarly produced individuals with unusual capabilities, and rarely results in the disabilities so common among Warchildren. Engineering of humans, except to eliminate the most severe genetic disorders, is considered a moral grey area, at best, but that doesn't stop everyone.
Aliens are rare on Earth -- it is considered an obscure backwater in the Galactic Union -- but some do visit. They may be diplomats, anthropologists studying human culture, tourists visiting a little-known but still charming planet, or fugitives hiding out. A few aliens have recently discovered that Earth's rapid technological advancement has brought it to technological parity in some areas with the Galactic Union, and many of the newest technologies even exceed what is known elsewhere in the galaxy. Earth may soon become much more well-known in the Milky Way. Few humans have, to date, left the planet, and most of those have only gone as far as the moon or Mars bases, or the various space stations in low Earth orbit. Recent rumors speak of a dimensional nexus discovered on Mars, but no one with less than a Top Secret clearance knows for sure.
The growing abundance of super-powered individuals, whether talented Warchildren, technological powerhouses, or visiting aliens, has put a severe strain on the normal police force's ability to keep order. Most police departments have powered up their SWAT teams, but publically available technologies are falling farther and farther beyond the leading edge. Some super-powered individuals have taken it upon themselves to act as vigilantes, countering the most severe superpowered threats.
Now it is time to organize complete teams of such individuals to take on these special threats. You will be a member of one of the first such teams, located in New York City. Before this, perhaps you have been a vigilante yourself, or a rare superpowered member of a regular police force or the military, or perhaps you are a newcomer who just recently gained your abilities or became motivated to use them for the public good. In any case, you must now prepare to face whatever danger faces the city or the world, whether it comes from rogue AIs, feuding gangs of Warchildren, alien invasion, or any other source.