Using the fire and rescue service (FRS) sector in Sweden as a case, this paper examines actors who engage in tasks that go beyond their traditional policy areas, and considers how their roles are shaped when interacting in new structures. This paper addresses two cross-sector collaborative practices: a) collaboration between the FRS and homecare nurses; and b) collaboration between the FRS and private security firms. The results show that discretion, occupational identity, expert-role expectations, and personal motivation are central to understanding how new frontline actor roles emerge and how they act within these collaborative arrangements.