Pula's Uljanik built the largest ship in the world. It was the greatest success of self-managing socialism. Three years after the launch, the ship mysteriously disappeared in the Pacific Ocean. The largest naval search so far was launched and after twenty days the ship was declared missing and the largest compensation in history was paid for it. Through intimate witness stories, conversations with shipbuilders, sailors and families of victims, using previously unpublished archival material, the film "Berge Istra" explores the secret of the disappearance of the Yugoslav Titanic, one of the greatest secrets in maritime history.Film presents exclusive material of two Spanish sailors who survived this tragedy.