Seeking to make upper secondary school physics more relevant and engaging, an online collaborative learning curriculum was designed. Each of the curriculum's lessons was structured as a goal-based scenario about human scientists on Mars. Video and audio data from the curriculum's implementation in Denmark was collected. This study utilized the theoretical lenses intersectionality, repertoires of practice, and epistemic agency. The use of comics as an analytical tool provided a novel and accessible way to depict the complex dynamics within the physics classroom. It allowed for a multimodal representation of the data and enabled a nuanced examination of the students' interactions. Findings suggest that interactions were shaped by the students' identities and these dynamics shaped their repertoires of practice. Moreover, the interactions had a profound impact on students' epistemic agency in physics. Collaborative learning with a goal-based scenario can include and empower diverse gender, racial, and language identities. It can also, however, work to disempower and exclude when the hegemonically white and masculine culture of physics is left unproblematized. This leads to the conclusion that if reform-based science education is untethered from a critical stance on socioscientific issues, students and teachers may reproduce social problems as much as they also may challenge them.