This study aimed to examine junior college students' group dialogues on the use of high-level comprehension features in an EFL reading class. The participants were one high-ability group and one low-ability group in terms of discussion proficiency. Eight representative discussions conducted in the students' first language served as the major data source, which were analyzed for discourse features linked to high-level thinking and comprehension, based on the criteria identified by Soter et al. (2008). Interviews and students' reading logs were collected to provide supporting evidence of how the EFL learners undertook their group reading tasks. The results revealed that both focus groups, to some extent, were able to incorporate all discourse features that indicate high-level learning and comprehension of texts without regard to discussion proficiency. The major differences were that the high-ability group had more uptake questions, whereas the low-ability group engaged in longer and more numerous episodes of elaborated explanations and of exploratory talk. That the low-ability group exhibited more talk and indicators of quality discussion than the high-ability group could be possibly explained with the genre of reading materials, personal belief about reading stories, and the use of nonverbal information and of personal connections. Despite the differences, the two groups demonstrated the language of high-level comprehension to "interthink" deeply about the text. The study concludes that through incorporating discourse features linked to high-level comprehension, students could guide one another toward deeper engagement with the text in group reading.