An old man dies in a hospice. It soon turns out that he did not succumb to his illness, but that he was suffocated with a pillow. But why kill a doomed man? Only a pile of old letters helps chief inspector Sonja Kruse to move forward with her investigation.
At the same time, Frank Berger uncovers a well-kept secret: As a young man, his father was a foreign legionary and fathered a daughter in Vietnam. Frank is shocked and takes his father to task. Because he chooses to remain silent, Frank decides to go on a quest for his step-sister and the love of his father’s life.
But someone is already waiting for him in Saigon: A German resident has received the unambiguous order: Frank Berger shall never reach his goal!