1917;- Christopher,McKechnie and Perowne have all been sent to fight in the trenches,surrounded by carnage and madness. When Bill,the commanding officer,suffers a breakdown from stress Christopher replaces him. Back home Valentine,whilst advocating that her fellow teachers read Marie Stopes' 'Married Love',shocks her mother by admitting that she would gladly be Christopher's mistress. Meanwhile Sylvia meets Gerald Drake again,home on leave,and once more has sex with him. As the war ends Christopher returns to Groby but Sylvia's selfish attitude sends him down to London and Valentine. Initially unwilling to divorce Sylvia,when she falsely claims to be terminally ill,Christopher decides he has had enough of her and changes his mind. To mark the end of the war - and an era - he celebrates with Valentine and his old army comrades.