Alex Krycek is a fictional character played by Nicholas Lea on the FOX television series The X-Files. Originally, the role of Krycek was offered to Callum Keith Rennie, who rejected it, but later made two guest appearances on the show.
Krycek has the highest known murder count of any recurring X-Files character, totaling 15: Augustus Cole ("Sleepless"), a cable car operator ("Ascension"), Duane Barry ("Ascension"), Bill Mulder ("Anasazi"), Melissa Scully, 2 fellow MIB assassins (while infected by the Black Oil;"Apocrypha"), a right-wing terrorist ("Tunguska"), a Syndicate courier ("Piper Maru"), a Russian scientist ("Patient X"), Dr. Kenneth Orgel ("S.R. 819"), an Alien Rebel ("Two Fathers"), Dr. Steven Sandoz ("Biogenesis"), and Michael Kritschgau ("The Sixth Extinction II: Amor Fati").
Krycek first appeared as an inexperienced FBI agent partnered with Mulder after Mulder and Scully are re-assigned to different sections ("Sleepless"). This is the only case he was seen to have investigated; it was quickly revealed that Krycek was actually an undercover operative, specifically a high ranking Man in Black subordinate to the Cigarette Smoking Man. After Scully reappeared, Krycek had seemingly abandoned the FBI Agent cover story, working exclusively for the Syndicate.
Krycek was seen switching sides as it suited him, occasionally helping both Mulder and the Cigarette Smoking Man as well as other people. It is safe to say that the only true loyalties he held were to himself. This, coupled with his diametrically opposed personality to Mulder, and his capability to seemingly stoop to any level, led to his being nicknamed "Ratboy" by X-Files fans.
Krycek played a direct part in several of The Syndicate's crimes that targeted Mulder and Scully. He assisted in Scully's abduction and killed abductee Duane Barry. He resurfaced again, and murdered Mulder's father, Bill ("Anasazi"). He was seen looming behind Bill Mulder just before he was shot and killed.
Later, Krycek was paired with Luis Cardinale, to kill Scully. Cardinale, however, accidentally mistook Scully's sister Melissa for Scully and killed her. Though the mistake was caused by Cardinale, Krycek, who was presumably in charge of the operation, was targeted by Cigarette Smoking Man for execution. Krycek then assaulted Assistant Director Walter Skinner and acquired a digital tape which revealed a US government cover-up regarding alien visits to Earth. Cigarette Smoking Man then attempted to dispatch Krycek with a car bomb, but he escaped. Krycek, on the run from the Syndicate as a renegade agent, disappeared to Hong Kong with the tape and sold information from the tape for leverage. Mulder followed Krycek to Hong Kong, and brought him back to America in custody. During this, whilst he was out of Mulder's sight, the black oil entity took control of Krycek, and carried on working for Mulder, up until Mulder's car was ambushed by Syndicate agents. Krycek, under the control of the "Black Oil", escaped and made a deal with the Cigarette Smoking Man for what was apparently the location of what is later found to be an alien spacecraft of some kind, stored in an abandoned missile silo in remote North Dakota. The Black Oil then transferred itself to the vessel, leaving Alex Krycek trapped in the silo, behind a locked blast door, at the end of "Apocrypha".
In "Tunguska", Krycek managed to break out of the silo and team up with a right-wing militia group. He handed the group over to Mulder, and offered information about a Mars rock. Mulder gained information from Marita Covarrubias about the rock's origin, which pointed him to Russia. Because Krycek spoke Russian, Mulder dragged him along. While searching for evidence, the two were caught and thrown in a gulag by Russian conspirators. Krycek, however, was soon free, as it was discovered he had ties to the Russian conspiracy, the weaker rival to the Syndicate. Mulder eventually escaped the gulag by taking Krycek hostage, and soon after, Krycek got away, but was stranded in the Siberian forest. He was "rescued" by other gulag fugitives, who had all amputated their left arms to protect themselves from the experiments conducted at the gulag, in which experimental vaccinations against the Black oil were administered to the left arm. They amputated Krycek's left arm against his will.
Krycek surfaced again, with a false left arm, working for the Russian conspiracy. He apprehended a witness to a cosmic event, and attempted to take him to America, along with a vaccine developed by the Russians. However, he was distracted by Marita Covarrubias, the two seemed to be in a relationship, and his witness was taken from him. He was then captured by the Syndicate. Willingly or unwillingly, Krycek gave the vaccine to the Syndicate. Knowing that there was a rebel faction among the alien colonists and that resistance was possible with the vaccine, Krycek warned Mulder not to give up his quest. However, he continued to work with the Syndicate; they hired him to draw Cigarette Smoking Man out of hiding.
In "SR 819", Krycek infected Skinner with nanotechnology. He controlled the technology in Skinner's bloodstream with a remote control, and used it to manipulate Skinner into carrying out his wishes. This leverage was seemingly employed during the events of "Biogenesis", "The Sixth Extinction" and "The Sixth Extinction: Amor Fati" as a means of using Skinner to obtain information on an alien spacecraft discovered by Scully in Africa.
In "Requiem", Krycek is released from a Tunisian prison by Marita Covarrubias, who claims that the Cigarette-Smoking Man is dying and wants him to recover a downed UFO. Krycek and Marita later conspire to kill the wheelchair-bound Cigarette-Smoking Man by pushing him down a flight of stairs.
In "DeadAlive", when Mulder was abducted and returned in a deathlike state, Krycek attempted to again blackmail Skinner, claiming that Scully's unborn child was a threat to humanity and must be destroyed. He propositioned Skinner to make sure the baby never came to term, in exchange for the means to save Mulder's life. Skinner refused, and promptly sent John Doggett to capture Krycek. After a short but intense fight, Krycek escaped. In "Existence" Krycek was shot in the forehead and killed by Assistant Director Skinner, during an unsuccessful attempt to kill Mulder.
Krycek's ghost briefly appeared to help Mulder escape a US Military Installation in the series finale.
Krycek appeared in the following episodes:
Tiny Creatures Defy Definitions of Death; Without Water, Animation is Suspended Series: LIFE ITSELF: UNRAVELING THE MYSTERIES OF BIOLOGY Series Number: 1/ 5
Dec 18, 1988; For centuries philosophers and scientists have puzzled over the nature of life-the essential property that a living organism has...