Stamboul Train (1932) and It's a Battlefield (1934) do not have single protagonists, but certain of their central characters, together with all of the protagonists of the other novels from Greene's first-published novel The Man Within (1929) through Brighton Rock (1938) have several qualities which taken collectively distinguish them from those of the later works.
First and most obviously, they are young men. Pinkie Brown, at seventeen, is the youngest, and Anthony Farrant, at thirty-two, seems oldest and most experienced and the only one whose character is more or less fully formed. All of the others undergo experiences that change them or at least have the potential to do so in some significant way, and even Anthony is brought to a crisis in which a single moment of the clearsightedness that characterizes his sister Kate could radically alter the course of his future. Anthony maintains wistfully and, it turns out, prophetically that he does not have a future, and the same can be said about many of the young protagonists to be discussed in these pages: Andrews, Crane, Conrad, Raven, Pinkie. The sense of doom hangs so heavily over their youth that to imagine them maturing into old or even middle age is impossible for the reader, as it seems to have been for the author. In later works Greene's characters will age as he does (though not as much), but the first-phase novels are centered around youthful protagonists.