Purpose: This research investigated whether structuring an inquiry-oriented professional learning network to include school-based co-teaching partners would amplify educators' success in taking up and adapting evidence-based understandings and practices as meaningful in their contexts. Our research questions were: (1) What conditions did educators identify in the PLN overall that supported their co-construction of knowledge and practice development together? and (2) How did including co-teaching partners in the PLN help participants to mobilize knowledge and/or practices in the contexts where they were working? Design/methodology/approach: A qualitative case study design was used because of its potential to examine how and why questions about complex processes as situated in context (Butler, 2011; Yin, 2014). A case study methodology allowed us to collect and coordinate multiple forms of evidence (i.e. interviews, teacher reflective writing, classroom artifacts, field notes) to examine both how conditions created within the PLN supported learning and how co-teaching partners were mobilizing what they were learning in their school contexts. Interviews were transcribed verbatim and data was analyzed abductively through an iterative and recursive process (Braun "et al.," 2018). Findings: Conditions within the PLN overall that participants identified as supportive to their knowledge mobilization and practice development included--having a shared focus, feeling accountability to the group, collaborative enactment of practices within the PLN, large group sharing and debriefing, sustained cycles of collaborative inquiry, affective support, valuing diversity and drawing from expert others as resources. Participants also identified the benefits that accrued specifically from working with co-teaching partners. In addition, findings showed how the degree to which partners engaged in rich forms of collaborative inquiry could be related to their learning and situated practice development. Originality/value: Findings show the generative potential of inviting co-teaching partners into a PLN to engage in collaborative inquiry with others. PLNs offer the benefit of engaging with educators from outside of one's practice context, which enables pushing their thinking in new directions. Our findings add to the literature by revealing how "in situ" knowledge mobilization can be amplified when educators participating within a PLN are also working through cycles of inquiry with a co-teaching partner. Overall, this study offers a PLN model where teachers have built-in support for knowledge co-creation and mobilization both within and outside of their school contexts.