Over the years University of Virginia professor Carol Ann Tomlinson has had several opportunities to teach with colleagues. Most of her experiences, both in her public school teaching days and at the university, have been quite positive and have contributed to her growth as a teacher. In this article Tomlinson describes her first, longest, and best teaching experience with a peer. For five years she was paired with another teacher who taught the same 7th grade language arts block. Their principal scheduled both teachers' language arts blocks at the same time, and they taught in adjoining classrooms. In essence, the teachers were co-teaching a total of 60-70 children in two-hour blocks as they used the shared door between the rooms to rearrange their students almost daily depending on what they were teaching and how they felt they could best serve particular students. Tomlinson reflects that throughout these five years of co-teaching, she and her colleague magnified each other's successes and minimized each other's failures. Herein, she discusses the rewards and occasional challenges of her experience tandem teaching.