Nina und Dora travel with their mother from the Netherlands to Croatia to spend the summer holiday at their aunt’s on a small island in the Adriatic sea. Thier cousin Ivo, whose father lost his life in a traffic accident, is at first very quiet and withdrawn. After some time, he accepts the both girls as his friends. His wish – and the wish of his deceased father – to revitalize the depopulated and fire-ravaged island takes the reader in a world of children adventures. Ivo’s secret is the search for a treasure without which no life on earth would be possible.