Three children in the port of Piran are sailing out to the open sea in a boat. They sing merrily, a white dove flying above them all the time. After a while they catch a sight of a boat sinking with a boy on it calling for help. The children help him aboard to safety ... The four children sail and sing. Not far from the shore they see a girl planting olive-tree branches. The children invite the girl to join them on the boat ... After a while they hear distant children's voice. There are a boy and a girl calling from inland. They would like to come aboard as well ... There is something strange happening at the bottom of the boat ...