Game of Thrones season 7 episode 1: The Harry Potter reference you might have missed

Fans of both Game of Thrones and Harry Potter were sent into a frenzy during the season seven premiere of the HBO hit series when the former seemed to reference JK Rowling's wizarding world.

The moment arrived in a scene between characters Samwell Tarly (John Bradley) and archmaester Marwyn, the man tasked with training him at...