The team takes on the case of a young boy from the Congo who has severe congenital heart anomalies; Murphy's latest encounter with his neighbor Lea has him confused.
Peter, unwittingly in a race against time with an ominous force, investigates Olivia's visit to a parallel universe.
As a comatose Scully fights for her life, Mulder uncovers clues to her abduction, leading to a confrontation with the Cigarette-Smoking Man.
The divers from a French salvage ship fall prey to a bizarre illness after working on a mysterious wreckage from World War II.