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 neighbour Lea has him confused.
The agents face their old foe, Alex Krycek, while pursuing a radioactive entity unleashed from a sunken WWII wreckage.
As a comatose Scully fights for her life, Mulder uncovers clues to her abduction, leading to a confrontation with the Cigarette-Smoking Man.