Detailed look at the line profiles of O IV 1400 and 1401 Å, Si IV 1402 Å, and C II 1335 and 1336 Å before the event (top), at thefirst maximum brightening (middle), and the second maximum brightening (bottom). The red lines show the modified profiles of Si IV 1394 Å, which are shifted in wavelength and scaled in intensity to roughly match the target lines (Si IV 1402 Å, O IV 1400 and 1401 Å, and C II 1335 and 1336 Å). These are shown for a better comparison of the profiles of the different lines. The wavelengths are given in Doppler-shift units relative to the rest wavelength of Si IV 1403 Å and C II 1335 Å. We do not overplot the Si IV 1394 Å profile on O IV 1401 Å at 09:34:25 UT because of the strong blend by the blue wing of Si IV 1402 Å. See Sect. 4.