Prominent magnetic activity over the course of two minutes during the pre-flare phase leading up to the flare, which started around 23:47 UT. Similar to Fig. 3C, we plotted the time-distance diagrams to capture the prominent coronal dynamics just before the flare. The positions of slits 1–5 are marked in Fig. 2. The speeds of reconnection flows along the slit are given. In panel E we plot the time series of EUV emission (gold, HRI_EUV; blue, SDO/AIA 335 Å) emerging from the foot region of the flaring flux rope. The foot region in the EUI images is outlined by the 25–50 keV contour in Fig. 1 (see the white box in Fig. 2 and the yellow circle in Fig. A.5). The hard X-ray emission time series in the 25–50 keV energy range is also shown (yellow, STIX; dark green, Fermi Gamma Ray Burst Monitor).