It feels as if it was written for serialisation. Although essentially a boys own adventure, it 's main interest now is the currency in 1939 of its writing and publishing and the events that were taking place in the European cities in which they are set. Hiram himself holds our interest because of the introspective element and the self doubt he suffers from. The use of well known areas and places in these cities allows us to feel closer to the action. And what's wrong with a happy ending? After all we know it's just romantic adventures for all ages. Somehow Imgarde seemed to leave a greater impression than Heidi.