Temporal evolution of the spectra taken with NTT/EFOSC2 (and the final X-shooter spectrum at +1868 days). The spectra are dominated by the Balmer series and a plethora of Fe II lines. The spectra are colored as indicated in the legend and the phases refer to rest-frame days after MJD 57577. Vertical solid lines indicate the position of hydrogen Balmer lines whereas the shaded pink areas mark the location of the strongest Fe II templates.