This is a story of a household in decline, although when Grace arrives at Riverton Manor, the home of Lord Ashbury, there is no indication that such would be the case. But the family line is first threatened by haemophilia in the male heirs, then the First World War plays its devastating part affecting the family both during and afterwards and finally, the suicide of poet Robbie Hunter on the manor grounds has a final profound impact on the family in crisis.

It's the Robbie Hunter suicide that opens the story, taking place at the lake on the grounds of Riverton Manor while attending a midsummer party. Witnessing his death are sisters Hannah and Emmeline Hartford as well as Grace herself. Hannah and Emmeline are the two characters who hold the majority of the fascination throughout the story and their lives are recounted through Grace's servile eyes.

Grace Reeves is now 99 years old and has been prompted to remember the events that have stayed with her so long by the visit of a director who is making a movie based around Hunter's death. Her questions have started Grace's mind ticking over and she begins to record her memories as letters to her writer grandson Marcus, who is suffering writers block after the tragic death of his own wife.

As a shy and timid 14 year old girl, Grace began her service at Riverton Manor, working as a housemaid. She was trained to go about her duties unnoticed by her employers and as a result was privy to many of the private conversations that took place. The crises facing Lord Ashbury and his family are revealed through Grace's narrative where she acts as a silent observer yet she is also invested emotionally in the drama that she talks about.

The occasional presence of Lord Ashbury's three grandchildren, Hannah, Emmeline and their older brother David is like a breath of fresh air for Grace because their ages are close to her own. Through their games and conversation she is able to escape into her own world of fun and adventure. It's their lives that become important to the story with Hannah in particular playing the most vital role when Grace later becomes her lady's maid.

Daily life at Riverton Manor is recounted in fresh detail bringing us up close to the machinations at work within the house as both upstairs and downstairs life portrayed. We are able to become comfortable with Grace's fellow servants from the gruff correctness of the butler Mr Hamilton to the brisk efficiency of cook Mrs Townsend, they soon become like family, trying to hold the place together.

The hints of a terrible secret are introduced right from the opening pages and while the tragedy of the suicide and the presence of the sisters cannot be denied Grace has been living with the guilt from that night for years. Only now, as her health rapidly deteriorates, does she reveal the secret she has promised to keep. In so doing, she tells the moving story of her life at Riverton. The hardships, tragedies, hopes, expectations, dreams and deaths are all remembered in vivid detail to reveal an incredibly absorbing story.

A significant feature of Kate Morton's prose is her ability to shift the focus effortlessly from the past back to the present as Grace proceeds to tell her story. There is a smooth seamlessness to the narrative that glides from the present back to the past, allowing Grace to tell her story while making the point that this old, old woman is near death. Her deteriorating health accompanied by increasing memory lapses and confusion grows in a poignant counterpoint to her youthfulness of the 1920s.

Largely because the story is told by such a very old woman, there is an almost overwhelming feeling of nostalgia laced with deep regret and a little sorrow about the events being related. You can feel the guilt that Grace has been burdened with as well as the relief she feels to be unloading herself through the telling of the story. Morton also does a wonderful job when displaying Grace's deteriorating health. The confusion, the tiredness and the acceptance creep insidiously into the narrative, building its own drama, raising the question of whether she will win the race to tell her story completely.

The Shifting Fog is an absolute triumph of emotion, a moving epic story that promises a dramatic conclusion from the opening page and does not fail to deliver.