The script of Harry Potter and the Cursed Child, the highly anticipated eighth installment in the Potter universe, was finally released in bookstores worldwide with unprecedented success on July 31. According to The New York Times, the play has sold more than 2 million hardcover copies within 48 hours of its release.

Cursed Child is based on an original new story by J.K. Rowling, Jack Thorne, and John Tiffany. The play — starring Jamie Parker, Paul Thornley, and Noma Dumezweni as Harry, Ron, and Hermione, respectively — was directed by Thorne, with the script written by Tiffany. The story picks up nineteen years after the Battle of Hogwarts, and deals with time-travel in a groundbreaking way that was previously never explored in the series. The story brings back many fan-favorites (both living and dead) and introduces two more young heroes: Albus Severus Potter and Scorpius Malfoy — the sons of Harry and his former arch-rival Draco, respectively.

Despite proclaiming itself to be a new, original story, Cursed Child disappointingly borrows much of its storyline from Rowling’s previous installments. The play often relies on “shock-factor” to keep the plot going, rather than rich detail and true emotional depth that is so characteristic of Rowling’s work. The script also noticeably lacks the familiar descriptive prose that distinguishes Rowling from the others, making the story difficult to visualize with only meager stage directions provided.

Also, many of Cursed Child’s profound revelations about the wizarding world seem a bit too far-fetched, and are at times inconsistent with what was previously explained in the series. Beloved characters are portrayed as poor caricatures of themselves; Ron Weasley, for instance, is reduced from a loyal, crucial member of the Golden Trio to a trivial form of comic-relief. As put by The Atlantic, “For all its compelling twists and turns, at many points [Cursed Child] feels like reading well-crafted fan fiction—the names are the same, and the characters feel familiar, but it’s apparent that they’re imitations nonetheless.”

This particular sentiment was echoed by many fans. With over 932 critical reviews, Cursed Child only has a 3.3 out of 5 star rating on Amazon.com as of August 4, 2016, despite being the online retailer’s most pre-ordered book of the year. Most reviewers cited its underdeveloped characters and outrageous plot twists as major sources of disappointment.

So despite the name on the cover, Harry Potter and the Cursed Child fails to evoke the kind of nostalgia expected from a continuation of a beloved series after nine years. The script may have worked well with a stage production, given the packed audiences and rave reviews at London’s West End, but fails to deliver as a stand-alone book.