The authors employ the ground rules of science and the standards of scientific evidence to examine paranormal phenomena such as UFOs, aliens, crop circles, and the alignment of the pyramids. A wide range of topics is discussed, including the reliability of eyewitness testimony, psychological research into why people want to believe in aliens and UFOs, and the role conspiratorial thinking plays in UFO culture. Prothero and Callahan also share their personal experiences of Area 51, Roswell, and other legendary sites.