Mind-reading. Foretelling the future. The ability to move objects without touching them. Being able to see distant and hidden objects with the mind. To most people, this sounds like the high points of the act of an illusionist, a person who uses trickery to baffle and confuse an audience while performing stage magic to achieve uncanny feats. But we all know these things really are impossible. Aren't they? The concept of what has become known as Extrasensory Perception (ESP) has existed for a century. This notion claims that certain seemingly impossible feats can be produced not by tricks but by using the human mind in ways that still aren't understood. Instances of telepathy, precognition, telekinesis, and remote viewing aren't confined to magic shows. It's well known that some people claim to have these abilities. What is less well known is that almost from the time the term ESP was first used, there have been attempts to use scientific investigation to find out whether they are real. In the beginning, these experiments were conducted by individuals or small organizations regarded as cranks by most members of the mainstream scientific community. Their findings were generally ignored, but that became more difficult in 1995 when previously secret documents were declassified. These revealed that a series of experiments on ESP had been funded by the CIA and DIA that cost millions of dollars and were carried out by respected scientists at Stanford Research International (SRI) in Menlo Park, California over the course of more than 15 years. It was certainly surprising that an American intelligence agency had been willing to fund research on subjects that were silly to most people, but what was perhaps more surprising was that the Soviet Union had already been involved in a very similar series of experiments. Most surprising of all were these experiments' findings: some people really did seem to have abilities that could not be explained by our conventional understanding of the physical world or the way in which humans interact with it. Respected scientists confirmed that they seemed to have identified a "class of interactions between consciousness and the physical world as yet unexplained." The claim that human consciousness can interact with the physical world in ways we do not understand seems astounding, and skeptics have widely challenged it, even as the findings of several experiments seemed to confirm that at least some people have latent abilities to do things that seem incredible. This is the fascinating, compelling, and contentious story of the quest to objectively and scientifically investigate ESP.