Yves Tréguier, a young orphan, escapes from a reform school in Brittany to join "Dédé la Glace" in Paris, an old-timer with whom he has a sincere friendship. The love of Zette, a young girl he has met, and the benevolent friendship of Father Blain, the bistro owner, give him the desire for regular work. "Jo le Grec", a pimp jealous of Dédé's friendship with Yves, seduces Wanda, a prostitute he loves, and shoots Dédé dead. Blain prevents him from doing the same to Yves, and shoots him in turn. Yves can live an honest life with Zette and the baby she's expecting.

In the 1953 elections, Piédalu was elected mayor of Marboue-Chambourcy. The esteem of his fellow citizens won him popularity, but he had to reckon with the wiles of his political opponents if he ran for deputy. The support of the son of one of his rivals, who loves Françoise Piédalu, and above all his stubborn common sense and natural malice, help him to overcome all obstacles.