A middle-aged insurer, after spending a sleepless night because of a quarrel with his wife, goes to the pharmacy to buy a sleeping pill. By mistake, the doctor, instead of giving him a sedative, gives him poison. The man goes out of town to visit a client and, unaware that he is wanted by the police, is more than once about to swallow the pills; but every time an obstacle prevents him from fulfilling his purpose.
This is the (funny) story of four agents of Roma traffic police in the '50s. Their life are crossed in affairs that often retire from mere job relationships. 'Guardia scelta' (special agent) Giuseppe tries to be a composer, he wants to write the anthem for the roman traffic police. 'Guardia'(agent) Alberto Randolfi has a too strong inclination to fine everyone and is dreaming about learning French. 'Brigadiere' (sergeant) Pietro Spaziali is busy looking at his little son Tonino and daughter Maria who is going to marry a boxer. The 'Maresciallo' (Marshal) tries to manage and solve all the troubles they often do.
Cesare Mancini is a tram driver who lives in Bologna. One day he accidentally hits a woman on a bicycle, the accident costs Cesare the relegation to a ticket seller.
Giovanni peddles useless pens in the streets of Rome with his sidekick Francesco, but his college-student daughter thinks he is a rich industrialist. She falls in love with a rich guy and when her father tells her the trust about their financial situation she drops her fiance and refuses food. Luckily, the guy's parents give their consent to the marriage anyway.
A destroyer departs from the port of Taranto with orders to take a load of petrol to Tobruk at all costs.
