Relentless weak magnetic reconnection marking the onset of a weak avalanche during the pre-flare phase. Panels A 1–16 are a sequence of HRI_EUV running-difference images at 2 s cadence showing the persistent unwinding of loops and their bidirectional separation near the X-shaped configuration in the complex loop system (indicated by green arrows). Similarly, in panels B 1–16, we show an event exhibiting rapid emission enhancement (green arrows) and subsequent explosive reconnection within the loop system. The location of this loop system within the flaring region is shown in the lower right panel of Fig. 2. In Panel C we plot the time-distance diagram, covering a duration of about 34 minutes, constructed along the slanted dashed line overlaid on panel A-1. The temporal extent of sequences shown in panels A and B is marked by the respective vertical solid lines. Ridges indicate the reconnection (bi-directional) flows moving along the slit, with their slopes giving the plane-of-sky speed. Representative speeds of such motions are given. An animated version of panels A and B is shown in movies S3 and S4.