The playscript of Harry Potter and the Cursed Child, Parts One and Two, which was released at midnight July 30 to coincide with the opening of the play in London, has set another book-selling record.

It sold more than 2 million copies in North America during its first 48 hours, according to Scholastic, and sold 680,000 print copies in the the U.K. first three days of release, according to a report in The Stage. That makes it the fastest-selling book since the 2007 release of the final Harry Potter novel. Sales figures for the first week of Cursed Child are expected to be published August 9.

The book hit number one on Amazon.com, and by mid-morning August 1 had already become the best-selling book of 2016 on the site.

Will it be the top-selling play of all time? Hard to say, since many of Shakespeare's classics have been on sale for hundreds of years in an untrackable number of editions. But publisher Scholastic has ordered a printing of 4.5 million copies, dwarfing the sale of most playscripts, which generally peak in the thousands.

Stuart Brynien, senior salesperson at the Drama Book Shop in Manhattan, told Playbill.com that recent best sellers among playscripts include Tony Award winner The Curious Incident of the Dog in the Night-Time and The Motherf**ker With the Hat, but said none of them came close to the total for the new Harry Potter play. “Everyone wants to know what happens to Harry Potter.”

There was a time when playscripts regularly sold like best-selling books, and ”Williams, Miller and Hellman will sell from now to Doomsday,” Brynien said. The 1962 musical Little Me contains the Carolyn Leigh lyric about the imagined best-selling status of a book in the window of Doubleday's book store:

As through a haze,
I see a Doubleday's,
And shining in a window full of Arthur Miller plays:
The truth!

A whole generation grew up during the years 1997-2007 breathlessly awaiting the release of each new book in J.K. Rowling's seven-volume Harry Potter series of fantasy novels about young witches and wizards battling evil. The books were released at midnight and parents would allow the young fans to stay up long past bedtime at the local bookstore to be the first to buy and read the latest installment.

That tradition was repeated at midnight between July 30 and 31 when the script for Harry Potter and the Cursed Child, Parts One and Two was released as a hardcover book, as the eighth book in the series.

Special release parties were held at more than 5,000 bookstores, according to The New York Times.

Rowling oversaw the writing and production of John Tiffany and Jack Thorne’s play, which began previews June 7 and opened officially July 30 at London's Palace Theatre. It runs five hours and 15 minutes with intermissions, and must be seen over the course of two performances.

The play finds Harry, Hermione and Ron now as adults. Here's how the story is described: “It was always difficult being Harry Potter and it isn’t much easier now that he is an overworked employee of the Ministry of Magic, a husband and father of three school-age children. While Harry grapples with a past that refuses to stay where it belongs, his youngest son Albus must struggle with the weight of a family legacy he never wanted. As past and present fuse ominously, both father and son learn the uncomfortable truth: sometimes, darkness comes from unexpected places.”

To book London tickets and for full performance schedules, visit HarryPotterthePlay.com.

(Updated August 3, 2016)