Sune and Sophie are going on a class trip, "the secret journey". It turns out it is the same date as Sune's favourite grandpa is getting remarried. And his grandpa wants Sune to be his best man. When at grandpa's he changes his mind. He has to go back to the classtrip. After this we are on a road trip, Sune is chasing Sophie and the class - and his parents are chasing Sune.