Contour plots showing the tangential (top row) and radial (middle row, six times larger scale in bottom row) critical curves of the ellipsoidal NFW lens with eccentricity e = 0.98 (left column), e = 0.9881 (central column), and e = 0.9986 (right column). Additionally plotted are: inflection curves (cyan), cusp curves (red), radial limiting curves (orange). Contours are plotted in the top row for κ_s = 0.125 and from 0.25 up in steps of 0.25 (integer-valued contours in black); in the top right panel only integer-valued contours are plotted for κ_s ≥ 1. The middle row includes contours from κ_s = 0.5 up in steps of 0.25 (integer-valued contours in black); in the middle right panel only contours in the interval 1 ≤ κ_s ≤ 10 are plotted. The bottom row includes integer-valued contours from κ_s = 1 to 20 (multiples of 5 in black).