Prior studies have shown how knowledge diffusion occurs in classrooms and structured small groups around assigned tasks yet have not begun to account for widespread knowledge sharing in more native, unstructured group settings found in online games and virtual worlds. In this paper, we describe and analyze how an insider gaming practice spread across a group of tween players ages 9-12 years in an after-school gaming club that simultaneously participated in a virtual world called Whyville.net. In order to understand how this practice proliferated, we followed the club members as they interacted with each other and members of the virtual world at large. Employing connective ethnography to trace the movements in learning and teaching this practice, we coordinated data records from videos, tracking data, field notes, and interviews. We found that club members took advantage of the different spaces, people, and times available to them across Whyville, the club, and even home and classroom spaces. By using an insider gaming practice, namely teleporting, rather than the more traditional individual person as our analytical lens, we were able to examine knowledge sharing and diffusion across the gaming spaces, including events in local small groups as well as encounters in the virtual world. In the discussion, we address methodological issues and design implications of our findings.