XMM photon image in the [0.5−2] keV band of a cosmic structure consisting of five groups of galaxies at a redshift of ~0.45 discovered in the XXL-N field (north to the top, east to the left). The size of the image is 20′ × 13′ and pixels are 12.5′′ × 12.5′′; the size of the XMM PSF is ~6′′ FWHM on axis. The colour scale gives the total number of photons collected per pixel. The contours indicate the underlying galaxy density within the 0.40 <z_phot< 0.50 slice. The small panels show CFHTLS urz images of each group. All five components are classified as C1 sources. For more details, see Paper VII.