After Ganino and Stilwell pitched him the new script, Piller suggested to producer Rick Berman that the story, not the script, be purchased. In a meeting, Piller told Ganino that he wanted to make changes to the story, which included the addition of Tasha Yar. Fearing that what they considered a better story would be lost if the changes were made to "Yesterday's Enterprise", Stillwell talked to Piller and pitched their Guardian of Forever story. While intrigued by elements of the story, Piller felt the use of the Guardian was a "gimmick" and wanted "The Next Generation" to stand on its own. Instead, Piller suggested that they merge the two stories, with Stillwell and Ganino sharing writing credit. Piller suggested that the "Enterprise" crew would immediately undergo a transformation due to the presence of the older "Enterprise", and that Guinan would be integral to the realization that something was wrong. Ganino and Stillwell were given two weeks to complete their new story.