The gradual release of confidential documents pertaining to a
top secret exchange program of twelve US military personnel to
Serpo, a planet of Zeta Reticuli, between the years 1965-78
http://www.serpo.org/information.html
In 1965, we had an exchange program with the aliens. We
carefully selected 12 military personnel; ten men and two women.
They were trained, vetted and carefully removed from the military
system. The 12 were skilled in various specialities.
Near the northern part of the Nevada Test Site, the aliens landed
and the 12 Americans left. One entity was left on Earth. The
original plan was for our 12 people to stay 10 years and then
return to Earth.
But something went wrong. The 12 remained until 1978, when they
were returned to the same location in Nevada. Seven men and one
woman returned. Two died on the alien's home planet. Four others
decided to remain, according to the returnees. Of the eight that
returned, all have died. The last survivor died in 2002.