2588: Necessary evils
All the unclued lights can be followed by the same word. Elsewhere, ignore three accents. Across 12 Positive Belgian forward cutting in has chances (10)13 Nabs informer admitting pressure (6)18 Memorial to fish-keeper ignores a question about Frank? (9)19 Flap about a kid whose name maybe on TV? (9)20 This monster turns 22, nearly (4)21
