This article discusses and elaborates on the insights gained from the teaching of a course in "Environment, Literature and Culture" at a university in the north of Thailand. The course was designed as an invitation to English major students to develop sustain-abilities (vulner-abilities, attend-abilities, and response-abilities). In an effort to overcome the anthropocentrism of traditional humanistic ecocritical pedagogies, both the course and this case study have been framed by posthumanist ontology and educational theory. From this standpoint, curriculum and pedagogy constitute a relational, open-ended, more-than-human entanglement of agencies, practices, discourses, matters, and encounters assembled in the process of teaching and learning. The dialogical and situated invitations of this course contributed to assemble a literacy situation that seemed to foster in students an embodied, affective, experienced, relational sense of becoming-together with nonhuman others. While it is unclear whether the participation in the course will continue to motivate their collective and individual actions beyond this literacy situation, the encounters and relations between these students and the many nonhumans assembled in the ecocritical classroom constitute by themselves bewildering learning experiences.