文森特·波莱尔(Thierry Lhermitte 饰)是一家大型建筑公司的老板,他事业有成,春风得意,妻子克莉丝蒂(Ophélie Winter 饰)美丽迷人,怀孕待产。与之形成鲜明对照,小人物西蒙·瓦里尔特(Michel Muller 饰)则过着穷困潦倒的生活。他是一名建筑专业的落榜生,如今则沦落街头,靠为人素描赚取生活费,几同乞丐。某天,西蒙路过一个建筑工地,惊奇地发现该建筑的设计竟出自他之手。原来,是文森特偷去了西蒙的创意,赚得盆满钵元。愤懑的西蒙前去讨要说法,却被粗鲁地赶了出去。 正所谓祸不单行,随即而来的车祸夺去西蒙的性命。一缕怨念盘桓人间,竟托生在文森特刚刚出世的儿子身上。从此,这个顽皮愤怒的小家伙向他的父亲展开了复仇……Simon is a down-on-his luck artist who gets no breaks from any quarter. While out working as a street sketch artist, he stumbles across the construction site for a new museum that is very obviously stolen from a design he created as an architecture student. Enraged, he storms into the office of architect Vincent Porel and demands an explanation, but is immediately hauled out by security. When the police arrive to arrest Simon, he makes a break for freedom, only to be accidentally struck down in the street by Porel himself. As Simon lays dying on the hood of Porel's car, his soul is transferred into the body of a newborn baby, none other than Porel's own son, born at that very instant. Remembering his past and realizing that he is now in the care of the man who stole his work and killed him, Simon resolves to make his new father's life hell.