 Eight books (all by McCaffrey alone) tell the story of telepathic, telekinetic individuals that become increasingly important to the proper function of interstellar society.Two civilisations in near-identical circumstances – an overlarge, lethargic population and a tragic history with sentient aliens – end up attempting to colonise the same planet by accident.What the humans do not know is that the people they have misidentified as nomadic natives are more technically advanced than themselves (and under no such illusions regarding the humans).