It is 1940 and Narrator Nick Jenkins is now in the army and England is now at war with Germany. Nick travels with his outfit to Wales and Ireland but returns to London for a weekend leave to attend a cocktail party with his pregnant wife.
For most of this series, Nick has interacted almost exclusively with his own class - the British middle/upper class and the London arts community. But in Valley, he meets many people outside his social stratum. This gives us a peek into a different part of society in England. The enlisted soldiers are drawn from working men, while the officers were bank managers and other professionals.
Powell includes satire of the military, from the incompetent general to the drunken aid.
This is a good opening to the 3-volume World War II cycle.