Time-distance plots of the Hα line core intensity (a) and LOS velocity (b) constructed along the artificial slits represented by the solid blue lines in Fig. 1. The three dashed magenta lines correspond to displacements of the transverse oscillations of the thread-like structures in the time-distance intensity plot. The events are numbered according to the order of occurrence. The dashed light green lines in the time-distance plot of the LOS velocity represent the same points.