This article explores the practice of one accomplished teacher who uses follow-up probes to press her fourth- and fifth-grade students to clarify and articulate their ideas more fully. Qualitative analysis of field notes, teacher and student interviews, and video recordings of instruction, and discourse analysis of reading conferences revealed four features of the classroom context that made it safe, sensible, and possible for this teacher to press students to extend their thinking during discussions. The teacher's positioning of students as capable and framing of reading as collaborative and interactive made questions that pressed students for elaboration fit naturally into instruction. (Contains 1 table.)