The Mysterians
The Mysterians then increase their demand, asking for a 75-mile-radius plot of land, as the Earth continues to develop a new method of attack. Earth's efforts in this matter pay off as a Markalite FAHP (Flying Atomic Heat Projector), a gigantic lens that can reflect the Mysterians’ weaponry, is designed. Meanwhile, the Mysterians kidnap Etsuko and Hiroko, causing Atsumi to search for, and locate, a cave entrance to a tunnel under the Mysterians' dome.