Carrying 800 passengers and their household goods, agricultural animals, and farm-related supplies to Earth's first interstellar colony, starship Origen's hyperdrive self-destructs, marooning its passengers near an Earth-twin planet orbiting an unknown solar-twin star. While settling in, the inadvertent colonists discover that Valeron is scattered with hundreds of thousands of alien replicator machines-but there are no aliens nor any other trace of them.

Each replicator is a shallow 8-foot-wide black stone-like bowl half-full of fine silver dust. Beside the bowl are two waist-high pillars about 8 inches in diameter, one pale silver, the other pale gold. Tap on either pillar, and the pillar makes a sound like a drum, one pillar high, the other low. Tap 256 times on the pillars in any sequence, and something surfaces in the bowl of dust. Simple sequences create simple and useful things like shovels, knives, rope, saws, lamps, glue and much else. Complex or random sequences create strangely shaped forms of silver-gray metal with no obvious use. 256 taps on the pillars can create any of 2256 different things; in scientific notation, 1.16 X 1077.

That's just short of one thing for every atom in the observable universe.

The artifacts are dubbed "drumlins," for the sounds the pillars make, and the replicators called "thingmakers." Drumlins have strange properties. Although virtually indestructible, drumlins can change shape, especially when doing so will prevent a human being from injury. Drumlin knives will not cut living human tissue, but it will cut living animal tissue or human corpses. Press a drumlin knife against your palm, and it will flow and flatten out to a disk. Pull the knife away, and it will slowly return to its form as a knife. Some claim that drumlins read human minds and grant wishes. Others insist they are haunted by invisible and perhaps hostile intelligences.

After 250 years on Valeron, the colony prospers. Starship Origen is still in orbit, and a cult-like research organization called the Bitspace Institute vows to repair Origen's hyperdrive and return to Earth. With millions of drumlins catalogued using the thingmakers, Valeron's people live well and begin to lose interest in returning to Earth. This threatens the Institute's mission, prompting it to launch a covert effort to undermine public faith in drumlins. A low-key war begins between the Institute and those who value drumlins-including several peculiar teen girls who have an unexplained rapport with the thingmakers and their mysterious masters.