This project developed and studied "The Source," an alternate reality game (ARG) designed to foster interest and knowledge related to science, technology, engineering, and math (STEM) among youth from populations underrepresented in STEM fields. ARGs are multiplayer games that engage participants across several media such as shared websites, social media, personal communications, and real-world settings to complete activities and collaborate with team members. "The Source" was a five-week summer program with 144 participants from Chicago aged 13 to 18 years. "The Source" incorporated six socio-contextual factors derived from three frameworks: Chang's (ERIC Digest, 2002) recommendations for engaging underrepresented populations in STEM careers, Lave and Wenger's (Cambridge University Press, 1991) situated learning model, and Barron's ("Human Development," 49(4); 193-224, 2006) learning ecology perspective. These factors aligned with the program's aims of promoting (1) social community and peer support, (2) collaboration and teamwork, (3) real-world relevance and investigative learning, (4) mentoring and exposure to STEM professionals, (5) hands-on activities to foster transferable skill building, and (6) interface with technology. This paper presents results from 10 focus groups and 10 individual interviews conducted with a subset of the 144 youth participants who completed the game. It describes how these six factors were realized through "The Source" and uses them as a lens for considering how "The Source" functioned pedagogically. Qualitative findings describe youth's perception of "The Source's" potential influence on STEM interest, engagement, and identity formation. Despite limitations, study results indicate that underrepresented youth can engage in an immersive, narrative, and game-based experience as a potential mechanism for piquing and developing STEM interest and skills, particularly among underrepresented youth.