However, "Cue for Treason" was written fairly early in his writing career, and was in a sense his definitive work. As well as being his best known, it has been described as creating the template on which he wrote many of his later novels. In particular, he has as his central character an adolescent male, who meets an adolescent female who proves a strong character in her own right. He also employs some plot devices which he sometimes used in his later works e.g. the heroine spends a large part of the story disguised as a boy, and to advance the plot the hero happens to overhear the villains talking. However, although in this case the hero and heroine marry at the end, he avoids this obvious ending in some of his later novels (e.g. "The Hills of Varna", which otherwise shows some similarity to "Cue for Treason").