Priori Incantatem, also known as the Reverse Spell, is a magical spell in the Harry Potter universe that reveals the most recent activity of a wizard’s wand. In the duel between Harry Potter and evil Lord Voldemort in Harry Potter and The Goblet of Fire, the Reverse Spell forces out of Lord Voldemort’s wand the ghostly images of the last half-dozen or so people he’d murdered, starting with the last person first and going in reverse order.
In the first printing of J. K. Rowling’s massive 734 novel (published in 2000), the last person murdered is the young and handsome Cedric Diggory, the champion of Hufflepuff House. The ghost of Cedric squeezes out of Lord Voldemort’s wand like smoke from an exhaust pipe (my description, not Rowling’s). “Hold on, Harry,” the ghost of Cedric says.
The next to the last person murdered is an elderly caretaker. His ghost, just like Cedric’s before him, encourages Harry to not give up. “You fight him, boy…” Then comes the ghost of Bertha Jorkins. “Don’t let go, now!” she cries. “Don’t let him get you, Harry…” Bertha, Cedric and the caretaker pace around Harry keeping the evil Death Eaters at bay. Next comes the heart stopping scene of watching Harry’s parents – the parents Harry never knew – appear as ghosts.
The smoky shadow of a tall man with untidy hair fell to the ground…looked at him… and Harry, his arms shaking madly now, looked back into the ghostly face of his father.
“Your mother’s coming…” he said quietly. “She wants to see you… it will be all right…hold on…”
And she came… first her head, then her body… a young woman with long hair, the smoky, shadowy form of Lily Potter…
The problem, as every Harry Potter reader knows, is that the order was wrong. Lily Potter (Harry’s mother) should have come out of the wand before James Potter (Harry’s father). JK Rowling messed up and messed up in a very large, very public way.

Rowling attributed the error to “late night writer’s fatigue” and it was fixed in later editions.
So this brings me to the question, how should authors handle mistakes AFTER publication. One of my writer friends says she never reads her work after it is published. It drives her crazy that she can no longer edit her work. She can no longer make any changes. She can no longer fix any errors. Any “fixing” is up to her publisher.
Which is one of the advantages of self-publishing. Self-publishing with Amazon, for instance, allows authors to edit their work as soon as they see an error. This won’t fix errors in the copies already sold but does allow the author to make changes to future copies. And maybe allows authors to rest a bit easier.

I’d like to hear from other authors. How do you deal with errors in published work? In the meantime, enjoy the movie magic of the Harry Potter and the Goblet of Fire Priori Incantatem scene.