Monica Julieta Reyes is a fictional character in the Fox science fiction-supernatural television series The X-Files. She is portrayed by Annabeth Gish. At first a Field Agent before becoming a Special Agent with the FBI, she works with her longtime friend and partner Special Agent John Doggett in the X-Files office, which is concerned with the investigation of paranormal cases, dubbed "X-Files". Introduced in the series' eighth season, Reyes would become a main character throughout the entirety of its ninth season, before returning for a single-episode guest appearance in the tenth season finale, and later in a recurring capacity during season eleven.
Season 8 (2000–01)
In 2001, Reyes was contacted by Doggett, now an FBI agent assigned to X-Files department, to assist in on a case involving the disappearances of several individuals who claimed to be alien abductees, as well as the disappearance of fellow agent Fox Mulder. Because of her background, Reyes considered that these believers may have simply formed a cult, but did not rule out the possibility of alien intervention. She stayed with the case until after Mulder was returned by his abductors, but returned to her field office soon after.
She later contacted Mulder, who was back to full health at the time, seeking help on a case she suspected had some link to the murder of Doggett's son. However, as before, she soon returned to her own work. Reyes remained with the New Orleans field office until she was called upon to protect agent Dana Scully in May 2001, driving her out to a remote location in Georgia so that the pregnant Scully might deliver her child out of harm's way. Reyes helped deliver the child, and made a permanent move soon afterwards, becoming Doggett's partner on The X-Files.
Season 9 (2001–02)
Season nine sees Reyes join the X-Files on a permanent basis, working with both John Doggett and Dana Scully. Following a year of investigating the paranormal, Doggett and Reyes were last seen in the New Mexico desert in 2002, where they were warning Agents Mulder and Scully of the arrival of Knowle Rohrer, a Super Soldier linked to the alien colonists. They were fleeing the scene as black helicopters destroyed the Anasazi adobes where The Smoking Man had been living. The X-Files office was closed shortly after the involvement of Walter Skinner and Alvin Kersh in Mulder's escape was revealed; Reyes still stayed with the FBI in some capacity for a time afterwards.
Between Seasons 9 and 10
Shortly after the closure of the X-Files, Reyes was contacted by the Smoking Man who had somehow survived his apparent death in "The Truth", albeit at the cost of suffering devastating injuries. In exchange for her assistance, he offered her a place amongst the survivors of the End Times, who would be spared from the effects of the "Spartan" virus, administered to the population via smallpox vaccinations. Shortly thereafter, Reyes departed from her career at the FBI, electing to take the Smoking Man's offer. She reluctantly spent the following decade aiding him in his cause with the Conspiracy of Men to develop a scheme to depopulate the planet, scheduled to begin in 2012.
Season 10 (2016)
Following multiple outbreaks nationwide linked to the Spartan virus, Reyes contacted Dana Scully in early 2016, willing to share the knowledge needed to develop an appropriate vaccine. During their meeting, Reyes revealed to Scully the circumstances behind her alliance with the Smoking Man. She also revealed that as a result of her abduction experience in 1994, Scully would be granted immunity from the Spartan virus. Reyes' new loyalties left Scully feeling temporarily betrayed. However, Scully refers to Reyes as a "trusted friend" when speaking to Agent Einstein, saying "it's not too late to stop it" when they begin working on a vaccine. She is not seen again in the episode.
Season 11 (2018)
In the eleventh season premiere, it is revealed that despite the events of the season ten finale "My Struggle II" being a part of Scully's vision, Monica is still working for The Smoking Man as one of his confidants and as a member of the new Syndicate. She apprehends her former Assistant Director Walter Skinner at gunpoint and offers to protect him from the Spartan virus if he finds Mulder and Scully's child, William, first.
In the season finale, "My Struggle IV", she contacts Mulder and Scully with information pertaining to their son, William, revealing that she is working from the inside to keep them safe. She later appears at the crime scene where William was last seen, and later takes The Smoking Man to Norfolk, Virginia where they have located him. During a confrontation with Walter Skinner, she is shot and probably killed.