Krychek

Alex Krycek is a fictional character in the long-running American science fiction show, The X-Files portrayed by Nicholas Lea. Initially introduced in the second season as a partner for main character Fox Mulder in the absence of his previous partner, Dana Scully, Krycek grew to become one of the show's primary antagonists, appearing in every subsequent season. 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 main antagonist, The Smoking Man, changing his allegiance when the situation suited him best.