Pregnant college student Lenore Harker leaves college before the end of the semester to move to an isolated house with her boyfriend Frank. When Lenore is ready to deliver the baby, they drive to the hospital. In the surgery room, the two doctors and the two nurses are found slaughtered and Lenore and the baby are found covered of blood. When Lenore is released, the family returns to Frank's house.

In 1972, a scale of measurement was established for alien encounters. When a UFO is sighted, it is called an encounter of the first kind. When evidence is collected, it is known as an encounter of the second kind. When contact is made with extraterrestrials, it is the third kind. The next level, abduction, is the fourth kind. Modern-day, Alaska, where-mysteriously since the 1960s-a disproportionate number of the population has been reported missing every year. Despite multiple FBI investigations of the region, the truth has never been discovered. Here in this remote region, psychologist Dr. Abigail Tyler began videotaping sessions with traumatized patients and unwittingly discovered some of the most disturbing evidence of alien abduction ever documented. The Fourth Kind exposes the terrified revelations of multiple witnesses. Their accounts of being visited by alien figures all share disturbingly identical details, the validity of which is investigated throughout the film.