Young Oliver meets the new Dutch girl in his small town: the free-spirited Erica Johansson. He finds her sitting cross-legged, in the shadow of the enormous oak tree in his backyard. Together they climb the tree and as they quietly observe a bird's nest, it marks the beginning of a beautiful friendship and an epic love.
Their fathers build a treehouse in that same sturdy oak tree. And while they grow up, the treehouse serves as a silent witness of them playing together, coming of age, sharing their first kiss and having their first fight.
As young adults we feel their struggle when they realize their feelings for each other have gone far beyond friendship. And when they finally embark on the most intense romance, they become inseparable and realize they are perfect for each other in every way.
However, an unfortunate turn of events makes it all screech to an abrupt halt and despite a desperate Oliver begging her to stay, Erica flees to Europe to get as far away from him as possible. Oliver then packs a bag and takes us with him on a journey across Europe, as he attempts to find the love of his life back...