Bob and Greta De Jaegher are happily married for ④0 years. They can look back on a rich and fulfilled life. Their ② sons Steve and Carl have a successful life as well. Steve is a talented and recognized film-director and Carl is a promising cook. Steve's wife Billie wrote a bestseller about happiness and wants to start a family with her husband. Brother-in-law Rik, who works at the zoo, tries to pick up his life with his kids, after his wife died two years ago. To mark their ④0th wedding anniversary, Bob and Greta organize a family weekend. They want to announce something very important. Their new plans are a sure hit for the family De Jaegher, but that's not the only thing - Wat had to be a cheerful gathering of the family, turns out to be something nobody expected.