The Green Hornet and Kato make their first appearance
As King Tut is repeating "The Black Museum, at Scotland Yard," his mouth looks to say "Scotland," however a steroypical Spanish sounding voice says "at Scotland Yard."
Marianna Hill plays a certain "Cleo Patrick" in this story - an obvious pun on "Cleopatra". There is another character of the same name in "Who Killed Molly?", a 1964 episode of "Burke's Law" in which Ms. Hill also appears - but in a different part.