For mystery fans searching for female sleuths in the same league as Sherlock Holmes, the pickings are pretty slim. So it’s no wonder that the new Netflix film Enola Holmes has become a breakout hit and rallying cry for young people searching for projects that center around non-male detectives.

Enola is Sherlock Holmes’s much smarter and more worldly teenage sister. Though her name may be lesser known, she’s been around for more than a decade. The film is based on Nancy Springer’s young adult mystery book series, which puts the intrepid teenage detective smack in the middle of the Holmes boys' club. If the movie has left you anxious for a sequel, you might want to pick up the books.

1. The Enola Holmes books bring an old fan theory back to life.

Springer’s six-part book series revives an old fan fiction about a third Holmes sibling. In William S. Baring-Gould’s Sherlock Holmes of Baker Street, Sherlock and Mycroft have an older brother named Sherrinford who manages the family estate. While the BBC's Sherlock conjured up Eurus Holmes, their secret sister, Springer’s books predate the hit series starring Benedict Cumberbatch. Published between 2006 and 2010, the Enola Holmes books borrow characters and themes from Sir Arthur Conan Doyle’s canon, but Enola is Springer’s own creation.

2. Netflix's Enola Holmes is largely based on the first book in the series, The Case of the Missing Marquess.

The first Enola Holmes book, 2006's The Case of the Missing Marquess, builds on Baring-Gould’s fan theory. Like Sherrinford, Enola and her mother inhabit Ferndell Hall, the Holmes family’s country estate. Enola meets her famous, semi-estranged brothers for the first time in 10 years after her mother disappears on the eve of her 14th birthday. Following clues involving anagrams and ciphers, she sets off for London to find her missing mother, and proves herself a worthy detective in her own right. The new Netflix adaptation closely mirrors this book.

3. Sherlock Holmes is often Enola Holmes's greatest antagonist.

Sherlock may seem rather open-minded in the Enola Holmes film, but in Springer's series he is sexist to the extreme and largely dismissive of his younger sister. "Thoughtful and imaginative perhaps, but certainly no stranger to the weakness, the irrationality of her sex," Sherlock says of Enola at one point. One of the most arresting aspects of Springer's series is the way the tables are turned on Sherlock: For the better part of the series, he is the bad guy—and Enola stands in great contrast to him.

4. Being a young woman is partly why Enola Holmes is able to regularly best her brothers.

Enola follows in the footsteps of her trailblazing suffragist mother, and disrupts her brothers’ attempts to cart her off to a finishing school. And she knows how to use the trappings of 19th-century womanhood (skirts, bustles, corsets, etc.) to her investigatory advantage. She solves cases that leave her much more experienced brothers baffled. In one instance, the brothers fail to track down some runaways because they don't realize what can be stored in a bustle. They don’t know the languages of fans, sealing-wax, or dangling handkerchiefs either, and thus find themselves being constantly outwitted by Enola.

5. Strong female bonds are at the heart of Enola Holmes.

Penguin Random House

Throughout the series, Enola alternates between trying to escape Sherlock and working with him to solve mysteries. In The Case of the Left-Handed Lady, Enola is determined to rescue the missing Lady Cecily—a young woman Enola does not know, but feels a strong kinship with and who is being held prisoner—so she disguises herself as a nun to save Cecily, and try to learn more about her own mother's whereabouts. But her disguise is also a way to evade her brothers and guard her own freedom.

6. Dr. Watson plays a part in Enola Holmes's life, too.

Dr. Watson is very much around in the books. He goes missing in The Case of the Bizarre Bouquets, but Sherlock doesn’t have the slightest clue as to where Watson could be. Enola is intrigued by the disappearance, especially when she learns that a bizarre bouquet—with flowers symbolizing death—has been delivered to the Watson residence. Getting involved in the hunt to find Watson could prove to be disastrous to Enola, since she’s still on the run from her brothers, but she’s determined to help and ends up beating Sherlock at his own game.

7. Netflix's Enola Holmes prompted a lawsuit from the Conan Doyle Estate.

Millie Bobby Brown and Helena Bonham Carter in Enola Holmes (2020).Alex Bailey/Legendary ©2020

Sherlock Holmes is one of the most adapted characters in literary history, in large part because the bulk of Sir Arthur Conan Doyle's books about the brilliant detective are in the public domain. Still, that didn't stop Conan Doyle's estate from suing Netflix over Enola Holmes based solely on the fact that the filmmakers dared to give Sherlock some actual, human feelings. Since it wasn't until the later Sherlock Holmes books—the ones that are still copyrighted—that Sherlock started to reveal shreds of his humanity, the lawsuit alleges that the Sherlock seen in Enola Holmes was based on the later, more emotion-prone Sherlock:

"After the stories that are now in the public domain, and before the Copyrighted Stories, the Great War happened. In World War I Conan Doyle lost his eldest son, Arthur Alleyne Kingsley. Four months later he lost his brother, Brigadier-general Innes Doyle. When Conan Doyle came back to Holmes in the Copyrighted Stories between 1923 and 1927, it was no longer enough that the Holmes character was the most brilliant rational and analytical mind. Holmes needed to be human. The character needed to develop human connection and empathy."

The lawsuit is ongoing.