This paper outlines the state of the art in qualitative longitudinal methodology, reflecting on more than 10 years of development since a previous special issue on qualitative longitudinal research was published by the "International Journal of Social Research Methodology" in 2003. The papers presented in this special issue emerge from a methodological innovation network that brought together an international community of researchers in order to map new frontiers for the method. This paper summarises the development of the method from a design to a sensibility, identifying three new frontiers as part of a future research agenda including: the need for a processual imaginary; experimentation with temporal perspectives and orientations and explicating the temporal affordances of our methods.