Fox Mulder and Dana Scully are still reeling from the death of their son William, but cautiously joyous about Scully´s unexpected pregnancy. Determined to raise this child together, Mulder and Scully struggle to find meaning away from the X-Files as they navigate the uncertain waters of their relationship. Then the FBI asks for their help tracking down two mysterious serial killers: one who seems to be able to control electricity, and another who disappears from the scene of the crime in what witnesses describe as a puff of smoke. It´s enough for the Bureau to re-open the X-Files - if Mulder and Scully are willing. They reluctantly agree, cautious about what it might mean for them and their unborn child but determined to find justice for the killers´ victims. But their return to the X-Files sparks the interest of a shadowy cabal, the heirs to the now-dead Syndicate, and Mulder and Scully soon discover that their investigation is connected to a worldwide threat on an unprecedented scale... one with their own future at its heart.