 Various Marvel writers, including Brian Michael Bendis, Mark Millar, Ed Brubaker and incoming Amazing Spider-Man writer Dan Slott had a hand in developing the story. During the course of the story's development, Quesada claims that he and Straczynski made plans to resurrect Gwen Stacy alongside Harry Osborn in the final chapter. This plot twist was discarded after numerous Marvel editors and writers lobbied for the character to remain dead. According to Quesada, Straczynski's original script for the storyline's fourth issue involved changes to continuity going as far back as 1971. Peter would have helped Harry Osborn get into rehab for his drug addiction immediately, which would have allowed a number of rewrites. Mary Jane would have remained in a relationship with Harry, Gwen would not have been killed and ultimately Peter's marriage to Mary Jane would not have taken place. Quesada realized that these changes would have far-reaching consequences for both historical and forthcoming storylines, so he made the decision to change Straczynski's story. While Peter and Mary Jane were to have remained a couple for the purposes of back-story, they were simply not a married couple. Quesada also described "One More Day" as an emotional climax of sorts and resolution for the relationship between Peter Parker and Tony Stark, who had developed a father-son-like bond during the "Civil War" storyline. However, Quesada hinted the paths of the two characters could cross again in the future due to planned storylines for Iron Man.
