In "Chuck Versus Agent X", Chuck, Ellie, and the rest of the team discover that the CIA and Orion created Volkoff as a cover for Agent X, an English scientist named Hartley Winterbottom and a close friend of Stephen Bartowski.
In "Chuck Versus the Cliffhanger", Chuck seeks out Volkoff to help him find a cure for the Norseman, which Vivian used on Sarah.