A former Olympic champion wants to compete in the Berlin Marathon one last time.

Rainer has everything he needs to be happy: a great job, a gorgeous wife and a designer apartment. And tonight, he absolutely wants to have a baby, which is bound to be great. Except that his partner would have liked to talk about it first. Lotte is feeling more and more the need to get some fresh air and take stock. She rushes off to the airport with the idea of getting away for a few days. At the airport bar, she meets Henrik, who has decided to change his life after the death of his wife and is about to leave for Australia...

The "Dagger of Batu Khan", a goldsmith's work from the 10th century that was thought to be lost, is discovered in a bricked-up cellar vault. Sebastian, whose father is the head curator at the "Green Vault" in Dresden, and his friends are allowed to help prepare the museum's exhibition of the dagger. They accidentally learn that the dagger is to be stolen and their lives are put in danger when they thwart the planned theft.