Rooted partially in the US sentimental tradition, neo-slave narratives often feature lyrical language, emphasize the emotional experience of enslaved characters, and evoke the reader’s sympathy and empathy. Highlighting the use of sentimental conventions in neo-slave narratives including Alex Haley’s Roots (1976), Octavia E. Butler’s Kindred (1979), Sherley Anne Williams’s Dessa Rose (1986), Toni Morrison’s Beloved (1987), Lawrence Hill’s The Book of Negroes (2007), and M. NourbeSe Philip’s Zong! (2008), this essay explores the tension between sentimentality and the radical political goals of neo-slave narratives. This essay analyzes Colson Whitehead’s The Underground Railroad (2016) as a neo-slave narrative that rejects rather than revises sentimental conventions. The novel’s central conceit, a literal subterranean rail network, illustrates how anti-Blackness, settler colonialism, and racial capitalism interlock to materially and discursively enable the US nation-state and liberal citizenship; sentimental conventions facilitate processes of containment and capture that allow this infrastructure to function smoothly rather than disrupting it. In contrast, Underground foregrounds the prosaic over the lyrical, veils the interiority of its characters, and unsettles the reader’s desire to feel with or for the humanity of the enslaved. The novel models an alternative way of engaging slavery as an infrastructure, gesturing toward a mode of fugitive affiliation premised on acts of tangible care rather than affective identification or the possession of interiority.