The 101 year old man Allan Karlsson goes through Europe in search for a Russian soda recipe he lost during the early 70s. Unfortunately, he is not the only one who is looking for it.

The sequel of "The 100 year-old man who climbed out the window and disappeared" continues with more flashbacks from Allan Karlsson long and adventurous double agent life. Allan introduces the Russian "folksoda" which ignite a new adventure.—Pontus Engström