Chief of Staff, General John P. Jumper was asked to appear in the episode. Jumper had originally been slated to appear the season prior, after taking over the role from Michael E. Ryan who had also appeared on the show, but was unable to make it to Vancouver due to the Iraq War. Originally appearing in three scenes set in The White House, Jumper was given additional scenes and dialog by the producers. Because of his position, Jumper was not paid for his role, with Air Force film coordinator Doug Thar remarking that Jumper had "a great time", joking that "he's not going to give up his day job". Members of the cast and crew were invited to dinner with Jumper and his wife during their stay in Vancouver. This episode is Don S. Davis' final appearance as a member of the main cast. Having portrayed General George Hammond since the shows inception, Davis felt it was time to move on, remarking that the "story line has made this the perfect opportunity for me to go away". Despite announcing his impending departure in late 2003, Davis did say that he was open to returning in a reduced capacity, "I love the show, I love my fellow actors, and the writers are excellent and if there's enough money, to put it grossly, certainly I'll come back". Showrunner and writer Robert C. Cooper felt that Richard Dean Anderson really embraced his transformation in the episode. Cooper had previously written the season 2 episode "The Fifth Race", where, as with the premise of "Lost City", O'Neill has the repository of the Ancients downloaded into his brain. Cooper felt that Anderson didn't previously enjoy it and was very reluctant when it came to speaking the Ancient language, but this time he took it much further. Anderson praised the guest cast of the episode, commenting on Jessica Steen that she was "very nice and smart and snappy and I really enjoyed working with her", as well as noting the performances of Devane and Cox. Anubis' commanding Jaffa, Her'ak played by Michael Adamthwaite makes his finale appearance on the show. Adamthwaite joked that he would skip to the end of the script every time he was asked to return to the role, anticipating that he would meet his demise. Reoccurring guest stars Tony Amendola, Ronny Cox, David Palffy, Gary Jones return for the episode, as Bra'tac,