Following the 1947 crash in Roswell, New Mexico an elemental alien race who has been visiting the Earth and other planets on good will missions throughout history find they are stranded. The Stepuli exchange technology for shelter, and as they integrate with humans in small communities, they are surprised to find children result. The Tracks We Leave takes place four generations in the future with their descendants. The government has incorporated them in a eugenics project and seek to exploit the Stepuli/human descendants for their abilities, and the potential of their genes.