Alex Krycek is a fictional character in the Fox science fiction-supernatural television series The X-Files. Alex Krycek is played by Nicholas Lea. He is initially introduced in the second season as a partner for FBI Special Agent Fox Mulder in the absence of his previous partner, Dana Scully. As the show progressed, Krycek grew to become one of the show's primary antagonists, appearing subsequently in every season until Season 9. Krycek's machinations frequently pitted him against Mulder, with whom he shared a complicated relationship. He was variously seen as either a henchman or enemy of the show's primary antagonist, The Smoking Man, changing his allegiance when the situation suited him best. Character arc Krycek is a Russian-American, the son of Cold War immigrants, who makes his first appearance in the season two episode "Sleepless", where as a young FBI Special Agent, he is assigned as a temporary investigation partner to Fox Mulder. Krycek proceeds to work with Mulder and attempts to gain his trust. It later becomes evident, however, that Krycek is actually an undercover agent working for the Smoking Man. Krycek plays an important part in several events that are harmful to Mulder and Dana Scully: he assists in Scully's abduction, and murders Mulder's father, William "Bill" Mulder. Krycek also assaults Assistant Director Walter Skinner and acquires a secret tape from him which reveals a US government coverup regarding alien visits to Earth. After a botched attempt on Scully results in the death of her sister, the Cigarette Smoking Man attempts to kill Krycek with a car bomb, but Krycek escapes. Krycek is later found to have been selling the secrets from the encrypted MJ files. Under the influence of the black oil, Krycek returns the tape to the Smoking Man, in return for knowledge of the location of an alien ship. The black oil-controlled Krycek goes to the ship, which has been moved to an abandoned missile silo in North Dakota. The black oil extracts itself from Krycek, leaving him locked indefinitely in the silo with the ship. Krycek is next found during an FBI raid, and taken into custody by Mulder and Scully. They learn that Krycek was recruited by an extremist militia group on a salvage hunt from the silo in North Dakota, and he informs the agents they must track the source of an extraterrestrial rock, brought to America by a foreign diplomat, to a