 Co @-@ writer Frank Spotnitz described the episode as a " fortunate accident " . Late in the fourth season of the show Gillian Anderson left the show for a week to film her part in the film The Mighty . The producers , knowing that they would have to write an episode without Dana Scully , decided it was not fair to have David Duchovny carry the same workload as in a normal episode considering her absence . As such , a story was devised in which his involvement would be light . This resulted in the decision to write , for the second year in a row , an episode focused on Assistant Director Walter Skinner ( Mitch Pileggi ) . Howard Gordon , having written the previous Skinner @-@ centric episode , " Avatar " joined Spotnitz and the two wrote the episode over a weekend while another Gordon written episode , " Synchrony " was in production . The writers felt that this was the perfect time to bring in Skinner 's deal with The Smoking Man ( William B. Davis ) to cure Scully 's cancer , made in the episode " Memento Mori " . Frank Spotnitz said of Skinner 's deal , " The hard thing for Skinner was that we had to keep him in the middle . We had him tell Mulder not to bargain with The Smoking Man in order to save Scully 's life . And then he himself struck a Faustian bargain with the Cigarette Smoking Man and was in his debt for some kind . " 
