Top panel: distribution of galaxies in the area of the supercluster XLSSsC N03 identified in XXL Paper XX. The galaxies are color-coded according to their spectroscopic redshifts in the GAMA database. The black circles indicate thelocations of the eight clusters/groups of galaxies that are known members of the supercluster. The two black squares indicate the location of the newly identified group associated with the Double Irony (in the upper right corner) and that of an overdensity of galaxies where a peculiar radio source (the “Unhinged”) is found. Bottom panel: GMRT 610 MHz image of the field. As in the upper panel, the size of the black circles indicates the extent (radius r₅₀₀) of the securely detected XXL clusters (C1 class). The three clusters circled in blue are C2 or C3 clusters whose sizes were not determined (in the C2 sample of XXL clusters, 50% of the sources are likely to be real detections; the C3 sample contains the most uncertain sources). The Double Irony radio galaxy can be seen in the upper right corner inside a square of 1 Mpc on the side. The location of the Unhinged radio source is also indicated by a red square.