The Hundred-Year-Old Man is back! Allan Karlsson is back! The hundred-year-old has had enough of his permanent vacation in Bali and is excited when a new adventure presents itself: during a hot air balloon ride, they run out of fuel and Allan and his companion Julius have to make an emergency landing in the sea. Fortunately, they are rescued. However, the bad luck is that the rescue boat turns out to be a North Korean warship heading for Pyongyang, where Kim Jong-un is flexing his muscles in the nuclear conflict. And just like that, Allan, who is quite knowledgeable about nuclear weapons, finds himself in the middle of a delicate political mission that will take him from North Korea to New York and then to the Congo. Along the way, he also encounters Donald Trump and Angela Merkel.