A terrible war once raged between the two rival planets within a distant solar system. Over the centuries their human inhabitants had 'adapted' themselves to the extremely different conditions of their new homes, far outside Polity influence. In the midst of this merciless conflict, one side encountered a bizarre object suspected of being a cosmic superstring employed as a new weapon by the rival side. Their attack on it caused the object to collapse into four parts, each found to be packed either with alien technology or some unknown form of life. Pending further study, these were quickly encased inside four separate Ozark cylinders and stored in a massively secure space station in orbit.
Sometime later, while conducting research on this alien entity, which they now call 'the Worm', a female scientist falls pregnant and subsequently gives birth to quads. She then inexplicably commits suicide by walking directly out into space.
The war was finally brought to an end by the use of new weapons arising as a result of research on the Worm. These weapons were deployed by giant space dreadnoughts nicknamed 'hilldiggers' - and their destructive power was sufficient to create entire new mountain ranges out of the vanquished planet's ravaged terrain. Twenty years after the dust has settled, those four exceptionally talented orphans have grown up to assume varying degrees of power and influence within a post-war society.
And one of this exceptional breed now seems determined to gain total control over the deadly hilldiggers. But why?