That medieval Muslim historians often copied episodes of early Islamic history from previous scholars is among the foundational (and incontrovertible) assumptions of the study of Islamic historiography. While this diachronic narrative stagnancy may often complicate efforts to utilize these stories as representatives of their times, our certainty that these writers were directly consulting and copying earlier versions allows us to read any alteration to the established source text as a conscious choice of the author. That choice may be motivated by any number of considerations, from transcription error, to style and brevity, to an attempt to alter the very meaning of the narrative itself. This paper argues that we may consider earlier versions of the narrative as the "script" of later versions, and that we can use the method that stage actors commonly term "beat marking" to make sense of these changes. The fundamental premise of "beat marking" is that every word in a script has a purpose or "objective" that must be "performed" by the actors. In our context, when a later author omits, adds, or alters material from an obviously copied source, it can be understood as the author, as an actor, choosing to "perform" that moment of the script in a consciously different way. By examining the impact that change has on the narrative, we may then be able to: 1) determine how important the change was to the author (i.e., was it motivated by the desire to change a moment, a character, an episode, or the entirety of the early Islamic narrative); 2) understand the literary-narrative strategies a given author likes to employ (i.e., what are his preferred tactics for accomplishing his objectives); and, finally 3) establish by aggregate each author's "super-objective" (his primary thematic or narrative concerns). Utilizing the ubiquitous al-Tabari as a "script" for later historians including Ibn al-Athir, Ibn Kathir, and others, this paper will 1) describe in detail this experimental methodology; and, 2) demonstrate the potential of this method to gain insight into the priorities, and perhaps the psychology, of the individual historians examined.