More than 100 years ago, in the town of Radcot “along the upper reaches of the Thames,” sits the Swan Inn, as famous for its storytelling as it is for its thatched roof. It’s here that “Once Upon a River,” the new novel by Diane Setterfield, begins.

The inn has been in the Ockwell family as long as anyone can remember. Even after Margot Ockwell married Joe Bliss and they had 13 children — 12 “robust” daughters and finally one son — the tales at the inn have always drawn more crowds than the drinks.

On Solstice night, the longest night of the year, those tales and drinks are interrupted by an injured man no one knows, a man who has clearly been at the mercy of the river. In his arms is a young girl. The man collapses. The child, as far as anyone can tell, has drowned.

Rita Sunday, the nurse and midwife for the town, is called in and is able to revive both of the strangers. As the town members try to discover what has happened, new questions arise almost as quickly as new tales are devised.

Who is this stranger? How did he come to be at The Swan? Why are there stains on his fingers?

Who is the child? What is the stranger’s relationship to her? Where has she come from? Most importantly, how was she able to come back to life after being pronounced dead?

The incident also gains the attention of three families in the vicinity, and each family will lay claim to the young 4-year-old.

Anthony Vaughan is rich. Yet even his wealth cannot comfort him or his wife, Helena, as they still grieve the kidnapping of their young daughter Amelia two years past. In fact, neither can ably make it through any of their days.

Living at Basketman’s Cottage on the other side of the river, on land that is “too wet even for watercress,” is the middle-aged housekeeper of the town’s parson. Emotionally unstable, she still goes by the name Lily White, even though Mr. White, if that was his name, deserted her five years ago. Lily comes to think of the young girl as her sister Ann, who sometimes returns in dreams and leaves water on the floors of Lily’s cottage.

Robert Armstrong, the illegitimate son of a local earl and an African serving girl, has made a good life for himself, even married the daughter of a local landowner. He comes to believe that the young girl from The Swan is the daughter of his estranged and profligate stepson, Robin, and the wife Robin has deserted.

That’s a lot of plot. However, Setterfield’s book never bogs down thanks to Rita Sunday, herself victimized by the restrictions placed on women in the 19th century. Her dealings with the three families making claims on the young girl keep the book afloat. We like Rita. We want her to find family, too.

Setterfield is particularly adept at describing the natural world, especially river life. Her almost metaphysical set pieces involving life along the River Thames are as spellbinding as her novel’s intricate plot.

Then there are the tales, all the tales, of the book. Some of the tales involve the real world, a world that her characters are mystified by, a world they need an explanation for.

For example, Vaughan thinks of the child he and his wife take in as “at once the cause of their happiness and the danger to it.” To deal with such a dichotomy, characters readily elaborate upon the tales they have already told, readily incorporating “a Seeing eye” and a magic lantern show, or Quietly the ferryman and “the drowned girl who came to life again.”

Diane Setterfield’s new novel is part mystery and part thriller, part bewitching fable and part subtle social commentary. But more than anything, it is about survival. It encourages storytelling as a tool to help us make it through our own worlds, for the world of “Once Upon a River” perhaps isn’t as far removed from ours as we would like to think.

Steven Whitton is a retired professor of English.