Agents Mulder and Scully return after 13 years to investigate a government conspiracy at the behest of a popular web-TV-show host, who introduces them to a woman who claims she's an alien abductee and shares startling news with them.

The season concludes with people all across the country falling gravely ill. A widespread panic develops and Scully looks within to find a cure. Meanwhile, Mulder confronts the man he believes to be behind it all, but another figure from Mulder and Scully's past may prove to be the key to their salvation.