The big day has come! Karel Bobrý, the greatest builder among beavers, is ceremonially opening his masterpiece - a huge dam that he built with his rat helpers. While the beaver dreams of admiration and fame, Lišák and Zajda are throwing a party with their animal friends. But in the morning they discover that their friend Výr has disappeared and their beloved forest is slowly being flooded.
The big day has come! Karel Bobrý, the greatest builder among beavers, is ceremonially opening his masterpiece – a huge dam that he built with his rat helpers. While the beaver dreams of admiration and fame, Lišák and Zajda are throwing a party with their animal friends. But in the morning they discover that their friend Výr has disappeared and their beloved forest is slowly being flooded. Is Karel and his dam to blame? Lišák and Zajda embark on an adventurous journey full of humor and tension to save Výr and their home. The well-known characters from the series come to life on the big screen for the first time, directed by Mascha Halberstad () and show the power of true friendship.