According to Spencer, the nurse included a letter in the package he had received asserting that the documents were taken from a series of interviews with an extra-terrestrial being in which she conducted as part of her official role in the U.S. Army Air Force.
The extra-terrestrial being in the interview was claiming as an engineer, pilot, and officer of The Domain Expeditionary Force. Their race has been using the asteroid belt in the solar system for the past 10,000 years as intergalactic base of operations.
The dying request of the nurse was that the transcripts finally be disclosed to the public. The nurse mentioned in the letter that the documents can answer to questions “Who are we? Where did mankind come from? What is the purpose of humanity in Earth?”