Evolution of a DF (from slit-02) across channels. Panel a.1 shows the bright (parabolic) track that the DF creates in the EUI X-T map. The four vertical lines mark the time stamps of snapshots in panels a.2, a.3, a.4, and, a.4, in which the white-arrows point toward the instantaneous position of the DF. Panels b-d have the same format but for AIA 171 Å, IRIS 1400 Å, IRIS 2796 Å observations. An animated version of this figure is available online.