It's the winter of 1860 when Richard Allen, a young curate, travels to a small hamlet outside Hereford to take up his first position. It's in this quiet place of wind and trees, birds and water that Richard is to fall passionately in love - but he cannot find fulfilment, for his lover is Susannah Beddoes, the wife of the vicar of his new parish. As Richard's feelings challenge him to his core, he develops a strange relationship with another woman, the solitary and eccentric Edith Clare. Against the backdrop of immense social and industrial change, the consequences of Richard and Susannah's affair are dramatic as they - as well as Oliver Beddoes - grapple with doubt and what it means to lose faith when the great certainties are in question. And throughout it all, the crossing-keeper's daughter Alice Birley - an observer of incidents and events she does not fully understand - has her own part to play...