A mysterious event causes everyone on the planet to simultaneously lose consciousness for 137 seconds, during which people see what appear to be visions of their lives approximately six months in the future—a global “flashforward”. A team of Los Angeles FBI agents, led by Stanford Wedeck (Vance) and spearheaded by Mark Benford (Fiennes), begin the process of determining what happened, why, and whether it will happen again. Benford contributes a unique perspective on the investigation; in his flashforward, he saw the results of six months of investigation that he had done on the flashforward event, and he and his team use those clues to recreate the investigation.
The team investigates a number of events related to the flashforward, including "Suspect Zero", who did not lose consciousness during the event, the sinister "D. Gibbons", and a similar mass loss of consciousness in Somalia in 1991. Meanwhile, personal revelations contained within the flashforwards occupy the personal lives of the principal characters. Mark Benford sees his alcoholism relapsing, his wife sees herself with another man, and other characters grapple with similarly unexpected or surprising revelations in their flashes forward.