In the spring and summer of 1997, four young women vanish in quick succession. Two of them go missing just off Texas Interstate 45, and the other two disappear just a few hours north. Could a serial killer be roaming the highways between Texas and Oklahoma? ABC News correspondent John Quiñones takes viewers inside the decades-long cold case investigation and four families' quest for answers. The report features exclusive footage of a hypnosis session with a fifth survivor that helped lead police to the killer and behind-the-scenes details into the killer's confession.