Knowing how “Fifty Shades of Grey” ends hasn’t made fans lose interest in the series. E.L. James’ latest installment, “Grey,” has sold over 1 million books in four days.

“Grey” was released on Thursday, and by Monday, Vintage Anchor Books announced that the novel had sold over 1.1 million books, Entertainment Weekly reports. As previously reported, the book topped several bestseller lists based on preorders alone.

While the numbers might shock some, they’re actually pretty on par with the rest of James’ trilogy. Within six weeks of publication, the “Fifty Shades of Grey” trilogy sold over 10 million copies, according to Publisher’s Weekly. Since James had been self-publishing the books before, Vintage decided to release the books all at once. Even with one book to sell instead of three, “Grey” could beat the record if it continues to sell at this pace. It’s already on its fifth printing, bringing the total of physical copies to 2.1 million.

James didn’t give audiences much notice for the release of "Grey." The 52-year-old author took to Twitter on June 1 to announce that the novel would be released on June 18, Christian Grey’s birthday. The date was fitting since “Grey” tells the events of “Fifty Shades of Grey” through the leading man’s eyes. The erotic novel shows Christian’s perspective as he, a wealthy businessman, falls in love with Anastasia Steele, a graduate student, and introduces her to BDSM.

“Grey” only follows the first novel in James’ trilogy, and it isn’t clear if she’ll write the other two books – “Fifty Shades Darker” and “Fifty Shades Freed” – from Christian’s point of view. It also hasn’t been announced if the fourth novel will get a movie adaptation, although actors Jamie Dornan and Dakota Johnson are reportedly only signed on for three films.

The “Fifty Shades” books have sold over 125 million copies, in digital, print and audiobook formats, worldwide.