Ever heard the saying that things tend to come in threes? Like this fun fact, for example!
The Mystery Begins was filmed at Templeton Secondary School, which was also used as a filming location for Smallville High on Smallville.
Continuing the Smallville theme, that series also had a story arc featuring The Mystery Begins' librarian (played by Lorena Gale) in a prominent role.
As a bonus fact, Gary Chalk, who played Vice Principal Grimes, actually attended high school at Templeton Secondary School in real life.
Thank you so much to @TheScoobyDoom for sharing this fun fact idea with me!!!