Watch HDToday. Calling All Earthlings explores a mid-century UFO cult led by one-time Howard Hughes confidante, George Van Tassel. Van Tassel claimed to have combined alien guidance with the writings of inventor/physicist Nikola Tesla, and other controversial science, to build an electromagnetic time machine he dubbed “The Integratron.” Was he insane? Or could the dome really break through the boundaries of space, time, and energy? FBI agents worked against Van Tassel and the alternative community that formed out of his work. Would he finish the Integratron before the government finished him?