This article explores the phenomenon of the call to professional public service in Canada. It draws on the testimonials of exemplars in Canada and elsewhere, and research findings from the fields of prosocial behaviour and public service motivation (PSM), and especially from motivational psychology, with its concepts of “flow” and “element,” to shed light on the dynamics of the call and steps professional public services can take to best mobilize individuals responding to it. The conclusion suggests there should be greater acknowledgement of the reality of the call, embeds the call in PSM theory, and sets out an agenda for research.