This chapter gives an overview of recent research into migrant journeys with an emphasis on the methods used to trace the displacement of people across international borders. I begin by addressing the ways in which displacement has been usefully conceptualised in this context through a focus on the nature of movement. This includes notions of truncated journeys, clandestine routes, and migrant trajectories understood as phases of movement and stasis (Collyer, 2010;Hage, 2009;Khosravi, 2014;Mainwaring & Brigden, 2016;Schapendonk, 2012). Whilst a lot of work in this area is inherently spatial, there is also a recent emphasis on describing migrant journeys through alternative temporalities, such as body chronologies or in relation to certain pivotal life events (Collins, 2018;Shubin, 2015). This work aims to understand the specificities of the experience of crossing borders without documentation, including the ways in which the border regime has made such journeys increasingly difficult and too often fatal. It also focuses on the role of a wide variety of actors, including people smugglers and border officials (Garelli & Tazzioli, 2018;Icli, Sever, & Sever, 2015;Macías-Rojas, 2018). Yet, there is an inherent contradiction and ambiguity in the use of methods such as tagging, tracking and tracing of individuals within research, since these are all key to how the border regime itself functions. In such a context, it is impossible for research to be either apolitical or neutral. Whether understood through the bureaucratised language of university ethical committees as the imperative to protect vulnerable participants, or understood as a personal ethical commitment towards those in precarious and often highly difficult situations, many researchers choose to take a stance that actively helps undocumented migrants. But this is of course not always the case, many research projects exist that are designed to help states govern their borders, whether in the form of new technologies of securitisation or through providing expert evidence to aid deportation (Hatton, 2018; "iBorderCtrl," 2016). 1