Uncle Erik is supposed to take the children on a vacation to Egypt, but he becomes sick. It looks like there won't be any trip to Egypt, which the children have been looking forward to for ages. However, it's decided that father will accompany them and everything goes well, until they're at the airport. Father misses the plane and the children find themselves alone in Cairo. Almost... Their neighbor and arch nemesis Mrs Flinth has also gone to Cairo, to meet her sister, who's married to the Danish ambassador. After some persuasion, Mrs Flinth agrees to look after the children during their stay in Egypt, but she drives a hard bargain. She wants to take them to boring museums and lectures, while they want to swim in the pool and go to the camel race. Will they once more find a way to get their will through? And will Mrs Flinth soften up?