Three collections of short stories that will expand on the Harry Potter universe will be published this fall, Time magazine reports. The books, which will cost about $3 each, will delve deeper into the “dark side” of the wizarding world. The e-books, each about 10,000 words long, will be available Sept. 6. The collections are presented by Pottermore, the Harry Potter website that J.K. Rowling made for fans of the books. “Pottermore Presents is intended to supplement the Harry Potter book series with short-form content that is entertaining and thematically curated by the Pottermore editorial team,” Pottermore CEO Susan Jurevics said. Heroism, Hardship and Dangerous Hobbies contains biographies of Professor Minerva McGonagall and Remus Lupin. Power, Politics and Pesky Poltergeists is about the life of Professor Dolores Umbridge, as well as the relationship between Voldemort and Professor Horace Slughorn while Tom Riddle was a student at Hogwarts. Hogwarts: An Incomplete and Unreliable Guide unfurls the secrets behind the walls of the ancient academy.