Peter and Katharina live in the same house, on the same floor, and grew up as neighbors' children. Peter is now a bus driver and Katharina is sitting at a post office counter. One day they both discover that they are no longer children and problems arise. Because there are also others who notice: In their high spirits with still inks wet driving license in their pockets, Katharina Peter's motorcycle "sunk" in a Berlin lake. Fortunately, a group of divers is there and heaves the good piece back on land.