Ken Follett's Hornet Flight is a historical thriller that retells a true story. Follett was inspired by a story written by former Special Operations Executive worker Leo Marks, in which two Danish teenagers found and repaired a biplane to fly to England. He combined this concept with the story of Danish Flight Lieutenant Thomas Sneum, who also flew to England in a rebuilt biplane along with pictures of a German radar station.
The novel begins in 1941, a time in World War II where Germany was consistently shooting down British planes. The story follows Danish 18-year-old Harald Olufsen, who discovers a radar installation by the Germans on his home island and photographs it to aid the Allies. He decides to go to England to deliver the information, but fears for his life and how this decision may harm his brother, Danish Air Force pilot Arne, and Arne's intelligence analyst fiance, Hermia. However, Harald is determined to deliver the film negatives himself, and enlists his friend Karen to help repair a ruined biplane in a nearby church to make the trip to England alone.