On his 50th birthday, a man who's been watching his weight, health and temper all his life suffers a heart attack. He's been doing everything he was told he should do and it still didn't help. He decides to turn the page and let loose.

To celebrate Yves’ 50th birthday, his friends plan to take him to the sunny paradise of Paros in Greece. But due to a cancelled flight, the holiday will take place in a far less glamorous and much rainier destination: Yves’ family home in Brittany. During the vacation, their bonds are challenged by Antoine’s constant complaining, Yves’ pride, Baptiste’s superstition and Laurent’s jealousy of Jean-Mich’s perfect life and family. On top of that, Antoine’s supposedly harmless joke – offering Yves a DNA ancestry test – has unforeseen consequences…