In order to provide increasing support for students with disabilities in inclusive classrooms in high-stakes testing contexts, some schools have implemented co-teaching models. This qualitative case study explores how 1 special education teacher (Anna) and 1 general education history teacher (John) make sense of working together in an inclusive World History I course in a high-stakes testing context (Virginia). Data collected included observations, interviews, curricular materials, and reflective memos. Analysis of these data indicate that John and Anna were "ambitious" collaborators--they offer an exemplary case of a special education teacher and a general education teacher developing a positive and productive working relationship, especially in coordinating their pedagogical performance within the classroom. However, in terms of how they made sense of instruction, it appeared as though Anna, the special educator, elucidated a slightly more ambitious vision in terms of her ability to think about how to connect history to students and how to teach beyond the test. John, on the other hand, appeared to be aware of, and concerned with, the high-stakes testing context. His concerns about behavior management and his narrow focus on his students' test scores appeared to influence every aspect of his thinking about history instruction. Implications for teacher education are discussed. (Contains 2 notes.)