C. S. Forester died before be could finish HORNBLOWER AND THE CRISIS, but from the notes that he left behind it is possible to see how the story would have ended.
Hornblower goes through a period of training in preparation for his spy mission. He brushes up his Spanish with a ruddy complexioned Count Miranda whom he is to accompany to Spain in the disguise of the Count’s servant. ‘He would have to watch every word and gesture, his life depended on doing nothing that would betray them.’ Then Hornblower goes through a crisis of conscience about becoming a spy.
As he is rowed towards the ship that will take him from Spithead to Spain Hornblower thinks: One stage farther along a hateful voyage. Each stroke of the boatman’s oars was carrying him nearer to a time of frightful strain; to something close to a certainty of a shameful and hideous death. .
He wonders whether to turn back, but sense of duty prevails.
Forged letters are delivered to Villeneuve which prompts the Frenchman to come out and fight. This is what Nelson wants.
It leads to the victory at Trafalgar. The course of history is changed.