The GDR, September 1989. The life of 12-year-old Fritzi changes along with the general atmosphere of the country. Her best friend Sophie had fled the country with her mother to West Germany via Hungary and the only thing Fritzi had left was Sophie's little dog Sputnik. Her friend had entrusted Fritzi with its care. But Fritzi misses Sophie's presence as much as the little four-legged friend. That's why she decides to take Sputnik back to Sophie. But there is only one way to get there: across the heavily guarded border. It's a very dangerous adventure for a 12-year-old girl and her little dog.