I can't find a source to quote or a clip to post, but in the first episode of the new X-Files miniseries, Mulder and the Old Man (Rance Howard) have a conversation outside at night. Mulder says, at one point:
Ten years ago, you came to me saying you couldn't take your secrets to your grave, that you couldn't live with it.
Is this incident Mulder refers to from ten years ago a previously established event? Or is it new to the story?