“The Inheritance” is the 10th of Charles Finch’s novels featuring the character Charles Lenox, an amateur sleuth who in the 1860s becomes London’s first private detective. The special pleasure of this series, beyond the mysteries Finch concocts, is how nicely he sets his stories against the background of Victorian England. It’s one of the more enjoyable history lessons you’ll come across.

The author Charles Finch (Timothy Greenfield-Sanders)

Finch, who is 36, was born in New York City, educated at Phillips Academy and Yale, then was off to graduate study at Oxford, where he still lives and writes. However, his fictional Lenox attended Harrow, which we’re told ranks with rival Eton as preeminent among the English public schools, “each a nursery for the aristocracy.” In “The Inheritance,” Lenox battles to save the life of a friend from Harrow, Gerald Leigh, who has become a celebrated scientist.

When the two met, the teenage Lenox was a handsome, athletic and well-born star on the Harrow campus. Leigh, by contrast, was small, surly, scornful of the school and scorned by his classmates, except for Lenox. Their friendship was an early sign of the independent mind that later would lead Lenox to give up his seat in Parliament to become a private detective. His fascination with crime was also influenced by his reading of penny dreadfuls from America and by Edgar Allan Poe’s stories of crime and detection.

This novel is set in 1877, when Lenox has been a detective for more than a decade. He has lost track of Leigh, only to have his friend abruptly reappear, by then a world famous scientist; he’s making a rare visit to London because he has been told a mysterious inheritance awaits him. Instead, gangsters try to kill him, for no clear reason, and he turns to Lenox for help.

Even as Lenox seeks to decipher the plot against Leigh, he’s pleased to introduce his old friend to his wife and daughter and to his partners in the detective agency. But even as Leigh is welcomed, and lionized by the Royal Society, the lawyer handling his unexplained inheritance is murdered.

It’s a good plot, but readers will also enjoy Finch’s digressions on life in mid-19th-century England. An earlier Lenox novel related his role in thwarting an attempt on the life of Queen Victoria. The queen doesn’t turn up here, but we meet her genial son, Prince Alfred, who chats about gifts for children and is convincingly described as “a creature without anxieties.” We also encounter Winston Churchill, but he’s only 4, out for a walk with his father. “Looks like a bulldog,” we’re told.

“The Inheritance” by Charles Finch (Minotaur)

Lenox, his late father and his older brother all served in Parliament, and he’s proud of their contribution to the nation’s social progress. Early in the century, his father helped pass the Factory Act, which decreed that children should work no more than 12 hours a day. “The story of their century had been that of the vote,” Lenox reflects, and he’s pleased that it has been extended from a select few to many thousands of men, although he thinks the vote for women is still decades away.

We’re given enticing glimpses of London life. Despite Queen Victoria’s uplifting influence, prostitution remains legal and highly visible on the streets. Indeed, we’re informed that Charles Dickens has founded a home where its practitioners might retire in relative comfort. We’re told that Lord Byron’s daughter, the Countess of Lovelace, “used her mathematical abilities to devise a system for betting horseraces and ended up penniless.” We learn that “In Lenox’s day the women’s engagement rings had been, without exception, of pearl and turquoise,” but the new vogue is for diamond rings, a style that Lenox finds garish.

Finch writes graceful prose that goes light on sex, violence and profanity. One winter day he has a woman declare, “It’s colder than a witch’s heart,” whereupon my own heart leapt with joy. All my life I’ve been hearing a less printable version of that expression, and it was reassuring to learn that only 140 years ago it was an entirely respectable phrase that a proper young woman might utter. As crime series go, the Lenox novels are exceptionally civilized.

Patrick Anderson regularly reviews mysteries and thrillers for The Washington Post.

The inheritance

By Charles Finch

Minotaur. 304 pp. $25.99