Downright Dencey by Caroline Dale Snedeker is a book of fiction written for young adult audiences. The book won the Newberry Honor Book award, which is a highly prestigious award in the young adult genre. It is considered to be one of the best books for young adults. Its popularity since the publishing date of 1927 proves the book's longevity and quality.

The book tells the story of Dionis "Dencey" Coffyn, a young Quaker girl living in Nantucket in the early 1800s. In the story, Dencey must learn to come to terms with her faith, her place in the world, and her own emotions and desires.

In chapter one, the reader meets Dionis "Dencey" Coffyn and her cousin and best friend Hopestill. Hopestill is a devout Quaker girl with strong roots in her faith and belief in God. Dencey, a tomboy, has problems with her faith and is not sure why it is so important. As a Quaker girl, Dencey is required to behave as her parents tell her, which means not disobeying any of the laws of the house or church. Dencey does not believe fully in the tenets of the Church and often acts not out of piety, but out of respect and fear of judgment and punishment.

Dencey's family situation is a common one for the residents of Nantucket. Dencey's father, Captain Tom Coffyn, is a captain of a whaling ship and is gone for the majority of the time. In Nantucket, it is not uncommon for the whalers to be gone for years at a time. On one trip, Captain Tom was gone for four years, traveling around the world, searching for whales. Meanwhile, Lydia stays at home with the children and manages the house and family. It is expected behavior of a devout Quaker wife and mother.

Dencey's dilemma begins when she throws a rock at Sammie Jetsam, an outcast often ridiculed by everyone in town. Dencey feels overcome by guilt and wickedness and is devastated when Sammie will not accept her apology. Dencey is determined to make it up to Sammie. One thing leads to another, and Dencey finds herself agreeing to teach Sammie to read in exchange for forgiveness.

Dencey must lie and break the rules in order to keep her promise to Sammie. Dencey is found out and is punished by her mother. Nothing will make Dencey change her mind about helping Sammie and maintaining their friendship. Dencey continues to get into trouble. Lydia cannot understand the sudden and drastic change in Dencey. Dencey's devotion becomes clear when she sneaks out in the night to prevent Sammie from sailing away with the horrible Professor Snubshoe, a man who Dencey is convinced will ruin Sammie's soul. Dencey gets lost and nearly dies. Sammie saves Dencey and gains respect from the Coffyns.

Sammie stays on at the Coffyns even after he is well enough to return to Injun Jill's cottage. Sammie begins to understand and adopt the ways of the Coffyns. Sammie finally begins to understand the family when he becomes a Quaker.

It is decided that Sammie will go out to sea like a proper young man. Shortly before Sammie leaves, he finally professes his love for Dencey and asks her to wait for him.