After they have graduated from school, the two best friends Kati and Jo jump into their purple Benz and embark on a journey around the world southwards. Kati, however, struggled with the decision for the journey as the love of her life returned to their hometown Tandern shortly before their departure. The journey leads the two friends over the Brenner pass, where their car suddenly stops working. When Kati then also learns that her grandfather is about to die, she wants to return home – this puts the friendship of the two to an acid test.

After they have graduated from school, the two best friends Kati and Jo jump into their purple Benz and embark on a journey around the world southwards. Kati, however, struggled with the decision for the journey as the love of her life returned to their hometown Tandern shortly before their departure. The journey leads the two friends over the Brenner pass, where their car suddenly stops working. When Kati then also learns that her grandfather is about to die, she wants to return home – this puts the friendship of the two to an acid test.