Twitter is widely recognised as a key medium for the dissemination of breaking news. Bruns & Burgess (2011) describe how ad hoc publics form, especially around shared hashtags, as events and issues become more widely recognised, and Hermida (2010) and Burns (2010) both describe this as Twitter’s “ambient news” function – always in the background, until trending stories push it into the foreground. What is less understood are the early moments of such ‘trending’, before hashtags and other mechanisms define a new story as breaking news. This paper explores these early processes: by tracking the dissemination of links to Australian news sites on an everyday basis as part of the ATNIX project (Bruns et al., 2013), we were able to trace the shift from sharing to trending from the very first links being shared on Twitter to the subsequent widespread dissemination of trending topics. We use innovative visualisation techniques to show the dynamics of this transition and to map the networks of interaction which emerge onto the overall Australian Twittersphere.