In this article, we examine an overlooked issue in research on school discipline: in-school suspension. Using data collected through observational methods, we present a detailed description and analysis of two in-school suspension rooms. These rooms operated in prominent, racially diverse middle schools in a large urban district. Applying critical theories of race and social exclusion, we reveal the ways that in-school suspension rooms constituted "deep," exclusionary discipline and cast "wide discipline nets" that disproportionately impacted Black students and Latino students for minor reasons and provided few educational opportunities. Due to the racialized nature of in-school suspension in otherwise "integrated" schools, the rooms themselves became segregated "internal racial colonies" with implications for the racial distribution of education as a social, political, and economic good.