After three decades of interviewing hundreds of people who have been contacted by extraterrestrial beings, Linda Moulton Howe has a compiled a taxonomy of the many types of non-human entities which have visited our planet. From grey-skinned humanoids to upright reptilians, she has uncovered a wide diversity of life capable of traversing vast cosmic expanses. She introduces us to her taxonomy of extraterrestrial beings on Earth and explores various motivations which have prompted their arrival. Some are new to the planet, while others have interacted with humanity for over 70,000 years and maintain close contact with Earth's governments.

Organizations within the U.S. government are not the only ones implicated in a vast conspiracy to conceal the alien presence on Earth. Linda Moulton Howe explains that branches of the British government actively worked to conceal the events and lingering consequences of the Rendlesham Forest incident. Documents leaked from these agencies include reports of non-ionizing radiation emitted from UFOs which cause lost time, memory erasure and tissue damage. None may have suffered more than John Burrows whose medical records were sealed after he was exposed to this radiation. It took the intervention of two U.S. Senators before he finally got the medical help he needed.