Luigi, a middle-aged engineer who, getting increasingly worried about the rising crime rate in his surroundings, follows the advice and example of his sleazy drinking cronies (whose relaxation activities include photographing nubile girls in the nude) to arm himself with the titular weapon; the problem is that he starts carrying – and, occasionally, brandishing – it with him everywhere (at his workplace, while taking a walk with his estranged wife Claudia Cardinale, etc.).