 Like humanity, they were not an interstellar race until the discovery of a space tunnel in their system, though they have been closing the gap quickly.Unlike humans, they did not discover the tunnel independently; it was, in fact, a Terran craft emerging into their home system that catapulted them onto the interstellar stage.The "Probability" novels shares two technological quirks with another of Nancy Kress' trilogies, the "Beggars" trilogy