Harry Potter and the Cursed Child, the newest dispatch from the Wizarding World of J.K. Rowling has officially hit stores, physical bookstores, as well as eBook stores around the world. The play on London’s West End has officially premiered, transitioning out of previews and into a running show. The play, both published and running, are important to the full story of Harry Potter, which began with the publication of Harry Potter and the Philosopher’s Stone in 1997 (1998 in the United States). After digesting the play in the printed form, here are some things that every Harry Potter fan should know.There be spoilers from here on out. If you missed our spoiler-free edition and want to wait to catch up, click over here.For Voldemort and Valor!Harry Potter and the Cursed Child might change how time travel works in the Wizarding WorldIn case you haven’t heard the news, the new Harry Potter story is heavy with the time travel. Which isn’t to say that this is the introduction of time travel to the franchise. In the third book, Harry Potter and the Prisoner of Azkaban, Hermione is given a magical device called a Time Turner to allow her to take twice the classes at Hogwarts. At the end of the book, Hermione and Harry use the Time Turner to save Buckbeak the Hippogriff and Harry from Dementors. In the book, the object is “turned” once per hour you would like to go back.The Time Turners were later destroyed by the Ministry of Magic and J.K. Rowling has acknowledged in interviews that the power to change time might not have been the best plot mechanic to introduce into the story. What saved Rowling with her portrayal of time travel in the book is that it was (arguably but not provably) a closed time loop. When Harry is first saved from Dementors by an unseen force in Prisoner of Azkaban, he thinks it is the ghost of his father when really it is Harry from the future. We don’t see a timeline where Harry is not saved from the Dementors because when Harry and Hermione go back in time, they have always gone back in time.In the play, not only are there two Time Turners that show up, but all the rules set by the previous Turner get changed. The first “prototype” Time Turner that Albus and Scorpius get ahold of in the play can take the users back years, but has a five minute time limit before it transports them back (and it exacts a physical cost, like breaking Albus’ arm). The original Time Turner didn’t have the power to jump the user forward and it certainly didn’t have the limitless power of Draco’s gold Time Turner from the end of the play. Most notably, because we’ve read Harry Potter and the Goblet of Fire, we know that Ron didn’t court Hermione with a fireworks display before the second task. That’s not a closed loop anymore, that’s creating alternate realities, which is a phrase that’s even name dropped in the play.If you’ve recently read Harry Potter and the Goblet of Fire, the plot will feel like Back to the Future Part II.Back to the Future Part II doesn’t just deliver the thrills of the first movie, it revisits the first movie when Marty has to correct his errors in the future (and by future, we mean 2015). Harry Potter and the Cursed Child pulls a similar trick by setting a lot of it’s action and spending much of the plot focus on the events in Harry Potter and the Goblet of Fire. Not only does Amos Diggory ask Harry to save Cedric, but eventually we re-visit all three of the tasks of the Tri-Wizard Tournament at least once, but we get trapped in an alternate dimension of Scorpius’ fourth year, just like how Marty gets trapped in a Donald Drumpf…er…Biff-run 1985.If that isn’t Back to the Future Part II enough, Cursed Child Part Two gets alternate universe Snape, Hermione, and Ron in on the action to undo time travel we saw previously in the play. Cursed Child loops back on itself and it loops back on the original series of Harry Potter books in a Back to the Future Part II way, and just when you think you are clear of the Bob Gale and Robert Zemeckis story mechanics, Cursed Child does a riff on the beginning to Back to the Future Part III except instead of the Old West, it’s Godric’s Hollow.Just sit down, enjoy your chocolate frogs and stay on the train!The Trolley Witch is literally a monster, and it is great.In one of the play’s most interesting scenes, it is revealed that the nameless Trolley Witch who goes up and down the halls of the Hogwarts Express selling sweets to children is actually some sort of wild-eyed and claw-handed ageless monster. Not only that but her Pumpkin Pasties are more like grenades.It turns out the Trolley Witch, whatever she actually is, is over 200 years old and was hired by Ottaline Gambol, the Minister of Magic from 1827 to 1835. Gambol introduced the Hogwarts Express to Britain and apparently had the Trolley Witch both serve snacks and keep people from escaping the train. After stopping Sirius Black and the Weasley Twins previously, Scorpius and Albus somehow manage to be the first kids to escape her grasp. This is the coolest new fact about the Wizarding World given by the play. The rest is all retread or re-writing parts of existing canon.Alex Price and Anthony Boyle as Draco and Scorpius MalfoyThe villain of the play isn’t revealed until the second half of Part Two… and it’s Voldemort’s daughterSpeaking about that “re-writing” part, the villain of Harry Potter and the Cursed Child is revealed to have been controlling all of these time travel shenanigans as a way of meeting her father, Lord Voldemort. It’s a big reveal that only comes after all the time travel to the Tri-Wizard tournament and the alternate universe plots have been resolved and no one stops to explain what happened.To be fair to the play, there is some foreshadowing in the previous three acts that Voldemort had a child. There is the rumor that Draco’s son Scorpius is actually Voldemort’s son by Time Turner (which seems like a ridiculous rumor until after the reveal of Voldemort’s daughter when it turns out the Malfoys DID have a Time Turner all along!) and when Scorpius travels to the alternate universe where Harry Potter died at the Battle of Hogwarts, there are references to “the Augury” which go unexplained because we don’t yet know Voldemort’s daughter exists. When Delphi (that’s her name) reveals herself, we find out the truth when Scorpius sees a tattoo of a bird (augury is divination by bird) on Delphi’s shoulder and realizes “the Augury” wasn’t a group, but Voldemort’s daughter who had risen to his right hand as she aged.It’s only a line, but Delphi reveals herself to be the daughter of Voldemort and Bellatrix Lestrange, born in Malfoy Manor before the Battle of Hogwarts… which could make sense. It has struck certain readers as odd that Voldemort, who so trusted Bellatrix, would have not assigned her the raid on Hogwarts the night Dumbledore was killed. If you count the months between Bellatrix’s release in book five to Dumbledore’s death in book six, it’s possible she’s absent from the raid because she’s just too pregnant.Regardless, Bellatrix’s disappearance for a part of Harry Potter and the Half-Blood Prince does provide a window for Delphi’s birth. At the end of the play, she’s sent to Azkaban and… presumably everyone is okay with the daughter of Voldemort still being around? We aren’t getting any more Harry Potter stories, so it looks like Voldemort’s daughter isn’t going to be the most popular offspring of a villain to date. Though she still rates above Godzilla’s child Manilla. Everything rates above that thing.