Emma Holt has been happily married for many years to the gardener of the local Quaker school. Headmaster Philip Manners, on the other hand, has been unhappily married to the Bishop's daughter for just as long. When Philip finds Emma in the school library, he can't help but be intrigued by her. Emma, dealing with her two eldest sons going off to war, is overloading herself with work to keep her mind focused. Philip, meanwhile, is trying to understand how his students could enlist when he teaches them pacifism, but is also struggling with his conscience: is he really falling in love with another man's wife? When conscription finally arrives and all the eligible men are called up, Emma and Philip find themselves unavoidably tangled up in each other's lives more and more. Emma is pushed to her limits with worrying about her sons and trying to juggle all her new duties, while Philip, ineligible to be called up, can't help but rush to comfort her when the worst happens overseas. With Emma torn between the loyalty she has for her husband and the passion she's been missing for so long with Philip, will she fight to hold on to Philip or stand back when events conspire to rip them apart for good?
