There is no greater happiness than making others happy! Perrine has lost her job and her motivation. Beyond fifty and on the verge of depression, she has written off happiness for herself. But then chance sends her a little dog who urgently needs her help. The encounter with the fox terrier lady awakens new spirits, and together they take their fate into their own hands, or rather their paws. Together they embark on a mission of happiness, which is under the motto: A good deed every day! Compliments are handed out (only honest ones!), garbage is collected, a homeless person is helped. Making others happy is contagious, and so Perrine soon finds herself at the head of a whole troop of people who want to do good. But the mission of the lucky agents is far from over!