Switzerland, 1873. Men from all over Europe are flocking to a tiny village to work on the biggest and most spectacular construction site of modern times: the Gotthard tunnel! The town is bursting at the seams and the prices for rooms are skyrocketing. In the bustle and confusion, three young people forge a friendship that defies differences of social class to tackle dramas together: the German engineer Max, lucid, balanced, born to a well-to-do family, a born mediator and shy suitor to the innkeeper's daughter, Anna. The lively, cocky young woman knows all about men - and about heartache: she decided to concentrate on business instead of love... And Tommaso? The hot-headed Italian from the lower classes is deeply, passionately in love with Anna and cannot hide his feelings. Max knows that he cannot challenge Tommaso for Anna's love, and soon, the trio faces a growing tension between Tommaso, who becomes the spokesman of the miners, and Max, who struggles to be loyal to his employer ...