It's been more than half a decade since the publication of the final "Harry Potter" book, but online fan forums continue to buzz with new theories about potential plot holes in the series.
With their endless quest to keep living the series, Potterheads can't seem to stop theorizing.
In book four, "Harry Potter and the Goblet of Fire," Harry and friends have the revelation that Ron Weasley's old rat, Scabbers, is actually Peter Pettigrew, a man who pretended to die years earlier.
If Peter appears on the map at the end of the book, when he's seen crawling into the tunnel under the Whomping Willow, shouldn't map holders (and Ron's brothers) Fred and George have discovered his true identity years before the fourth book takes place?
There's no exact answer to the plot hole, but fans are passionate about a few theories.
It may be that Hogwarts is too crowded to keep tabs on every name or the twins just never bothered to look in on their own brother and his lowly pet rat.
Based on the details provided in the books, it seems as if Fred and George memorized the school's secrets long before the fourth book and largely stopped using the map.
If that's the case, they probably never noticed Peter Pettigrew on the map.
Incidentally, that explanation also accounts for other strange happenings, like not noting their sister, Ginny, spending quite a bit of time in an abandoned bathroom during book two.