Prepare to be shocked, Potter fans.
McGonagall, per J.K. Rowling's novels and the world of Pottermore, appears to have been born in 1935, while the action in Fantastic Beasts: The Crimes of Grindelwald takes place in 1927, some eight years before she was born.
That's all because of its proposed introduction of a young Professor McGonagall, who in the original Potter series served as the Head of Gryffindor House and as a key ally of the titular wizard.
Fans have pointed out that McGonagall wasn't born until 1935 - almost a decade after the first Fantastic Beasts installment is set.
The film will bow into United Kingdom and U.S. theatres on November 16. So, fingers crossed that she at least gets an action sequence or two during Fantastic Beasts.
Which other characters might Rowling prematurely bring into the wizarding realm?
Fantastic Beasts: The Crimes of Grindelwald is being directed by David Yates, from a screenplay by J.K. Rowling, and produced by David Heyman, J.K. Rowling, Steve Kloves and Lionel Wigram.
Glascott will be the second actress to play the character, following on from acting royalty Dame Maggie Smith's turn as McGonagall in the original Harry Potter film series. The most recent trailer for the film revealed that Voldemort's snake, Nagini, was actually once a woman - a detail that was never previously disclosed and caused quite an uproar among the fandom. We'll have to wait and see...
The film is slated to release in India on 16 November.