This study investigated secondary school students' engagement in epistemic and narrative practices of chemistry in the context of a chemistry story on gas behavior. Argumentation is an example of an epistemic practice in science and stories are one kind of narrative (Ricoeur, 1981). By using a chemistry story, the authors hoped to engage students in the argumentation processes by linking chemistry knowledge to everyday contexts (Erduran and Pabuccu, 2012). Student group discussions and written frames during the activity were used as data sources. Analysis of these student outcomes concentrated on (a) the nature of the students' discourse; (b) the quality of students' argumentation; and (c) students' conceptual understanding of gas behaviors. The authors categorized the nature of group discourse using five different codes, determined the quality of student argumentation by counting the number of rebuttals, and measured conceptual understanding through students' answers in the writing frames. The results of this study add to the literature seeking to understand how to develop students' engagement in the argumentation process, how to enhance the quality of students' argumentations, and how to improve their conceptual understanding of gas behaviors.