Two cousins, Duduś Fąferski and Poldek Wanatowicz, have just finished their school year and they want to spend their holidays at the seashore. They decide to go for their first trip on their own. The trouble is that Duduś is a sissy, who cannot even tie his own laces and Poldek dreams of adventures like in Jack London's books. With no money, and presumed lost, they invent the strangest ways to accomplish their dream and get to the seashore. How will this adventurous trip end?