Колишній клоун Чак і школяр Стьопа мандрують в минуле. Їхня мета - дізнатися від Чакового предка таємницю весел-зілля, загадкової трави, від якої люди починають сміятися.
Vsevolod Zinoviiovych Nestaiko or Nestayko (Ukrainian: Всеволод Нестайко) is considered Ukraine's best-known and best loved children's literature writer. He wrote and published stories, fairy tales, novels and plays over many years, and his books have been translated into twenty languages around the world, including English, German, French, Spanish, Russian, Arabic, Bengali, Hungarian, Romanian, Bulgarian, and Slovak. Nestayko's works are included in school curricula in Ukraine.