This is a spoiler if you haven’t already read “A Larger Universe”

Prologue (to “An Emergent Universe”)

Look down on a spinning ice skater, her arms extended, her hands trailing ribbons of sparkling threads.  Dotted with crystals and eight times longer than the skater’s outstretched reach, the ribbons spiral around the rotating figure, individual threads weaving an intricate braid of light.  Look closer.  The ribbons are not as regular as they first appear.  Wind whips the braids, splitting two ribbons into four.  Some of the threads are broken, shorter than the others, and those threads fly away in patterns of their own, drawn with, but not part of the weave.  Now extinguish the lights of the rink except for a single, focused, spotlight from above.  Crystals on the skater’s arms and head flash, but her black costume hides the body that holds everything together.  All you see are gleaming diamonds, spiraling in the dark.

Hold that image in your mind.  It is the Milky Way galaxy, seen from above: the spirals form a disk, one hundred thousand light-years across, containing at least one hundred billion stars.  Focus on one of those broken threads, half-way around one of the major braids and twenty-six thousand light-years from the galactic center.  This fat thread, the Orion Spur, contains hundreds of thousands of stars and is some three thousand light years across and ten thousand light years in length, but it is still a single thread of the thousands that make up the braids that are the Milky Way.  Insignificant among the stars in the Orion Spur, about half-way along the thread, is Earth and its sun.

For thousands of years, advanced civilizations in the Orion Spur had been dominated by the Kadiil.  No one had ever seen a Kadiil, and they made no attempt to rule.  Instead, they slowed or ruthlessly suppressed the acquisition of certain kinds of knowledge.

The Kadiil watched every intelligent species.  When a civilization developed radio, the Kadiil enclosed their star system with a spherical communications barrier that removed all meaningful signals, both incoming and outgoing.  Kadiil ships first showed themselves when a culture left its birth planet and showed signs of understanding the nature of gravity and the deep structure of the universe.  To each of these species, the Kadiil offered faster than light travel.  They demanded, in return, the end of specific types of research and no conflict with others.  Civilizations that agreed to this bargain received unlimited numbers of sealed drives that, when mounted in ships, gave them access to the stars.  Those that refused, or accepted the drives but continued their research, or attacked other planets, were destroyed, their home planets reduced to rubble.

Two thousand years ago, a species calling themselves “the People” (Nesu in their language) was one of those civilizations. They took the bargain, but secretly continued their research even as they launched starships.  After the Kadiil destroyed the Nesu’s home planet, Liran (in English, Stream), the remaining Nesu became homeless wanderers and survived by trading with other star faring species and with those less technically advanced.

As the centuries passed and their situation became more desperate, the Nesu turned to violence to meet their needs.  Some preyed on other ships in acts of piracy.  All found it expedient to enslave members of primitive species to do the tasks they could no longer be bothered to do.

A thousand years ago, the humans of a medieval English village on Earth were taken and trained to work in and maintain one ship, the Nesu Tol (The People’s Hand).  Five years ago, the Nesu on that same ship kidnapped a thirteen-year-old human boy with knowledge of Earth’s computers.  That boy, Tommy Yates, then eighteen, led a successful rebellion against the Nesu and took control of their ship.  He then discovered the true nature of the Kadiil, and used that knowledge to defeat them, releasing all of the worlds in the Orion Spur from their dominance.

Two months before, the Kadiil had appeared over Earth to propose their bargain.  They never returned to receive Earth’s answer.

The communications barriers enclosing civilizations like that of Earth disappeared with the Kadiil.  Approximately seven hours later, radio broadcasts from hundreds of other civilizations, some of them centuries old, were received on Earth.  Tommy returned to Earth to find governments in panic and unwilling to allow him to land.

Of all of the star faring civilizations in the Orion Spur, only the Nesu and humans from one ship knew of their new freedom.  The unlimited supply of star drives ended when the Kadiil were defeated.  Everyone must soon suspect.