Although Fox's X-Files Revival still doesn't have an official title yet, the cast keeps getting bigger and bigger. The Hollywood Reporter has word that Robbie Amell (The Flash) and Lauren Ambrose (Dig) have signed on for guest-starring arcs. Both actors will appear in the fourth episode of the six-episode event series, portraying a pair of new FBI agents.

Robbie Amell is portraying Agent Miller, described as "smart" and "smooth." Lauren Ambrose's Agent Einstein is said to be "sharp" and "confident." It isn't known if both of these characters will be partners on the show, or how they will be involved in the story. Production is currently taking place in Vancouver, the same city where The Flash is shot. Robbie Amell revealed in an interview last month that he starts shooting The Flash Season 2 in July. The actor's co-star Victor Garber, who plays the other half of Firestorm, said that they will both be featured in the Season 2 premiere.

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Robbie Amell and Lauren Ambrose join a cast that includes returning X-Files stars David Duchovny (Fox Mulder), Gillian Anderson (Dana Scully), Mitch Pileggi (Walter Skinner) and William B. Davis (The Cigarette Smoking Man). Confirmed guest stars include Joel McHale, Annet Mahendru, Rhys Darby and Kumail Nanjiani. There have been rumors that Robert Patrick and Annabeth Gish will return as John Doggett and Monica Reyes, but their involvement has yet to be confirmed.

Chris Carter, who created the original series, returns to write and executive producer along with original writer/producers Glen Morgan, James Wong and Darin Morgan. There was also a rumor that the second episode, entitled "Home Again", will be a sequel to the beloved Season 4 episode "Home", but that turned out to be untrue. The new series is set to debut Sunday, January 24 on Fox, immediately following the NFC Championship Game.

Robbie Amell is also believed to be joining The Flash spinoff DC's Legends of Tomorrow, alongside Victor Garber, but his involvement has not been confirmed yet. The actor most recently starred on the big screen in The DUFF. Lauren Ambrose starred in the USA Network event series Dig. What do you think about these new additions to the X-Files cast?