Eons ago a starfaring race came to Earth, intending to help the humans with
impending floods (caused by glacial melting). This first mission was intended to
build a "beam station" that would allow faster ships to follow. But their ship
crashed and they were stranded on Earth, minus many of the specialists and materials
that were needed to accomplish that mission. The starfolk had "Landers", crafts capable
of navigating the solar system, but not suitable for the light-years journey
back to their home planet.
The starfolk started the arduous process of developing local technology to a
level capable of building the beam station. To get sufficient manpower for this
massive undertaking, the starfolk had to enlist the help of the humans. In exchange,
the starfolk tried to improve the quality of life of the humans. They
promised to take the humans with them to their home planet, described as "paradise".
The humans revered the visitors as gods. Over time many of the starfolk intermarried
with the humans.
The work progressed slowly. Supplies of fuel and materials ran out, and finally the
last Lander exploded in midair, killing many of the starfolk. The humans viewed
this as a fall of their gods and rejected the starfolk. Thus the humans turned from
worship to persecution, forcing the starfolk to go into hiding.
The starfolk were heartbroken over their losses and the broken promises to
the humans.