Zoomed-in view of the area outlined by the white box in Fig. 2. A strong moat flow is observed near the jet base and is marked with a black arrow in panel a. Four main positive- and negative-polarity patches are labelled as P1, P2, N1, and N2 respectively. The blow-out jet in the coronal EUV 174 Å image, associated with a chromospheric surge in Hα, is indicated with grey arrow in panels b and c. Fibrils and the ‘X’-shaped saddle-point structure are marked in the Hα image. A flaring loop associated with the chromospheric fibril singularity is shown in EUI and Hα. Potential-field extrapolations on the PHI magnetogram are shown in panels d–e. In panel d, the yellow arrow indicates the jet base, which consists of a fan-spine configuration with a null point and associated outer spine towards the west (black arrow). A zoomed-in version is shown in panel e, where several inverted ‘Y’ structures are shown from the weak magnetic corridor between N1 and N2.