The narrator explains what he's doing in Devon – he's a soldier.
During the "Falling Stage," the hero falls under a "dark power." Early in the story, we don't exactly know why war is a "dark power" yet, but we do know that war is generally considered to be a bad thing.
The interlude with Esmé and Charles in the tearoom.
This peaceful afternoon in the tearoom is kind of the calm before the storm. The soldier knows that he's about to depart for military action, and we know that the threat of battle is immanent. However, he's still able to enjoy this reprieve from the war.
The beginning of "the squalid, or moving, part of the story" – the shift from the narrator to Sergeant X (105).
Time has elapsed, and a lot has happened in the life of the soldier over the last year. He's seen action at D-Day and beyond, and now that the war in Europe is over, his soul has yet to recover. Sergeant X, as he's now known, is emotionally numb and alienated from his former self.
The narrator sarcastically lashes back at Clay (137).
This is not the soldier we knew from the tearoom – all of a sudden, we see just how much the war has warped him. We worry, as he does, that he'll never find himself again.
Sergeant X reads Esmé's letter.
During the "Rebirth Stage," the hero is redeemed, usually by a woman or child. Esmé (who is fortuitously both a young woman and a child) helps the soldier reconnect with the world, and with his old self. Finally, there's light at the end of the tunnel – it looks like he just might pull through.