In an alternate universe: Event 16 (or “Harry Potter and The Crimson King”)

In an alternate universe, J.K. Rowling partners with Stephen King to write a Harry Potter novel in which it is revealed that the recently defeated Lord Voldemort was a servant of the Crimson King.  When low men in the Crimson King’s employ begin using muggles  to hunt down and capture magically-inclined people, the American counterpart to Hogwart’s summons forth a ka-tet of gunslingers, led by Cuthbert Allgood via his death at the Battle of Jericho Hill, from another level of the Tower to do away with these villains.  

Through the course of the story, Randall Flagg is unmasked as having assumed the form of the American “defense against the dark arts” instructor, and Harry Potter himself turns out to be the villain directing these abductions as the Crimson King possessed his body using a glass from the Wizard’s Rainbow, capable of facilitating possession.  The novel ends with Cuthbert Allgood killing Harry Potter, who is then resurrected by the Wizard Maerlyn who has left the solitude of his cave on another level of the Tower long enough to save Potter and place him as the new head of Hogwart’s before returning with Cuthbert to the magic school’s American counterpart.  Cuthbert is then sent to New York where he gets a job as the head of security and black bag operations for the Tet Corporation.