[PTTG]

2011: An alien spacecraft plummets into the atmosphere in mid may; the massive craft was more than two kilometers long before it broke up on entry. Despite its size and presumably interstellar velocity, there was a proportionately minor destruction on Earth. The debris field stretches from the Gulf of Mexico, along the east coast of the USA, across the North Atlantic, over the southern coast of Great Britain, through the heart of continental Europe and into Turkey, and finally the heaviest debris is scattered throughout the Syrian Desert.

The ship was originally designed to explore potentially life-bearing planets and Earth was its next destination. A cosmic accident "sterilized" the ship, not only killing the alien crewmembers but also resetting most of its navigational equipment. When it finally fell out of jump-space a few months before its earth rendezvous, it resumed its fairly low speed relative to earth, which is one reason why it wasn't a relativistic impactor.

The debris is scattered randomly over a wide spectrum of land and sea, and some chunks are the size of a city block. Even a piece of hull a few centimeters across has fascinating and extraordinary properties.

Early examination shows that there are several distinct compounds in the wreckage:

An extremely high specific strength metaloid, nonconductive/nonmagnetic, dense, and with very high melting point. Used as exterior plating, fairly common. Glossy and matte black, depending on the surface.

An ultra-high temperature superconductor (up to ~800C). It is present in both a dense mesh and as well as wire. It is also a superb fiber-optic material.

A much lighter structural material with somewhat lower specific strength. The most common material; it's superior to titanium in most respects, but compared to the other materials it's not that impressive. It has a dark green sheen, and is sometimes called Harbenite.

An exotic material that slows chemical reactions by an unknown means. It's a clear liquid that denatures into a kind of chemical sludge when exposed to high heat; few samples of it survived.

A radioactive compound that has a variable half-life. When provided an electric charge, this material provides increasing amounts of radiation; with no charge, it is detectably radioactive but not extremely dangerous. Some wag named it Quadium. Nobody knows how it works, but the first guess is nanomachines.

Computronium, a lusterless silver material that appears to be a self-organizing computing substance. No humans have yet figured out how to build a computer interface with it, but if they could, they'd find that its storage space, processing speed, and parallel processing capacity all scale with the square root of the mass, and it far outperforms any existing technology.

Quantities of osmium, gold, platinum, manganese, and a few other rare metals are also common in the rubble, and that's aside from the exotic value of materials from the alien spacecraft.

Additionally, there are a number of artifacts with additional capabilities. Only a few have so far been recovered and defined:

Statues. There were a number of abstract but clearly artistic sculptures in the ship, many of them made of the extremely rugged materials the ship is made from.

Extremely durable storage casks about .3 meters tall and wide. Nobody knows what is inside them; they are even stronger than the hull plating material and are extremely rare. In fact, they are fuel canisters containing antimatter. Fortunately for humans, they are self-powering. If someone does manage to crack one open, there's 10 grams of antimatter in there (minus a trivial amount that device consumes to power itself), and it would produce an explosion around 430 kilotons.

Power cells are the most common artifact. They are trapezoidal, approximately 8x3x2 cm. They use superconductor loops to store energy, but apparently have a magnetic shield making them safe and easy to handle.

There are few actual weapons in the debris. The ones that have been found are about a meter long and, like the storage casks, have no apparent control system. Each one does have two replacable power cells in ports, and it takes standard power cells. After dismantling one, researchers found a controlable subsystem that produces a pulsed laser that functions in space and in atmosphere well, and one cell lasts for 12 shots.

One fairly common device is a small force field generator; the 10-cm wide projector produces a tunable "plate" of force up to 1m away and 2m wide. It can also tune from high impenetrability (a very high divisor DR) down to cushion-softness. It is always laterally frictionless.

This is a simple setting: Superscience falls from the sky into the modern day, now deal with it. Add in a gold rush in some of the most populated and most chaotic parts of the globe, plus the potential for even more extreme discoveries, and it's a busy place. For one thing, nobody knows where the propulsion system landed...