The film is based on a series of immensely popular Swedish children's books, about the boy Bert, who is just hitting puberty and having the usual problems with it. But that's where the usual ends abruptly.
Something strange has been spotted over the tree tops in the forest where Charlie Strap and Froggy Ball live, and Plåt-Niklas quickly builds a monocular to examine it. It turns out to be an emergency signal and the two friends together with Plåt-Niklas and The Parrot set out on an expedition to resque whoever is sending the signal.
