The one thing that true fans of "The X-Files" have always known about the show is the main theme -- "the truth is out there" -- but a new teaser trailer released by Fox this week for the upcoming reboot of the series questions that assertion.

According to Entertainment Weekly, the new limited run revival of "The X-Files" will expose a lie, and it may unravel the very basis of the original series.

In the clip, Agent Fox Mulder (David Duchovny) questions himself, along with everything that he and his X-Files associates have worked for over the past few decades.

"What if our work, the X-Files, everything we've been led to believe in is a lie?" Mulder asks Agent Skinner (Mitch Pileggi) in the promo teaser, which aired during last Monday's episode of "Gotham."

Mulder has apparently stumbled onto a new conspiracy theory. His revelations in the upcoming series could well lead to all new story arcs and put avid fans into a frenzy for more.

The limited series, which is slated to appear on Fox after an NFL playoff game on Jan. 24, will no doubt leave fans of the show wanting much more. Fans could even demand a full season from the network, as they have in the recent past.

Agent Dana Scully (Gillian Anderson) was also in the promo. She was seen introducing herself and Mulder to a person who appeared to be on the floor from the camera angle.

The limited series event will feature a six-episode run next winter, and fans of the show are chomping at the bit to find out what happens next.

Check out the trailer below.