The series focuses on a group of boys from the Rychlé šípy Club who venture into the mysterious urban district of Stínadla, where they uncover various local secrets.

[3] Roles of older boys (Vonts) and adults were mostly played by well-known actors, while only Roman Skamene, who was fifteen at the time, continued to work in the acting profession from the representatives of the Rychlé šípy.

A group of five honest and brave boys who call themselves the Rychlé šípy undertake all sorts of activities and quests for fun and adventure.

Mirek Dušín, Jarka Metelka, Rychlonožka, Červenáček and Jindra Hojer learn one day about a mysterious puzzle - hedgehog in a cage, which is supposed to be of great value to the so-called Vont movement.

In the spring of 1967, the director Hynek Bočan came up with the idea to make a feature film based on the novels Záhada hlavolamu and Stínadla se bouří, who, after the approval of their author Jaroslav Foglar, started writing the script together with Václav Šašek.