An ex-Marine with a stern sense of duty, the Bureau's Assistant Director Walter Skinner has little patience with Agent Mulder's unorthodox methods of investigation. More than once he has warned Mulder and Scully that their inquiries were crossing into dangerous territory, and once he shut down the X-Files entirely. But when Scully was kidnapped, he re-opened them, telling Mulder, ‘That's what they fear the most’ -- without clarifying who ‘they’ are. It's never clear whose side Skinner is on, or whose orders he takes, but his efforts on behalf of Mulder and Scully ‘through unofficial channels’ have made it plain that he is deeply concerned about his independent-minded agents and their work. He was very concerned about Agent Scully's brain tumor and he tried to help her by making a deal with the Cigarette-Smoking Man (‘Zero-Sum’). In ‘Redux’ Scully falsely suspects him to be her and Mulder’s enemy, while the truth is that he is withholding evidence about Mulder’s faked death to protect them. It turns out that Section Chief Blevins was the man who worked for the conspiracy. In ‘The End’ Agents Mulder and Scully are re- assigned to work under A.D. Kersh to investigate Domestic Terrorism. As we learn in ‘Triangle’ Skinner is even forbidden to have contact with Mulder and Scully. Nevertheless he helps Agent Scully in this episode by providing her with much needed information which she desperately seeks in order to save Mulder’s life. He is rewarded by a very surprising kiss by Agent Scully. Mulder and Scully are re-assigned to the X-Files after the events in 'Two Fathers / One Son' and A.D. Skinner is again their direct superior.