If you’re a fan of The Big Bang Theory, you might know that the show initially premiered with an entirely different pilot episode.

As far as most people are aware, the first episode of the series introduces main characters Sheldon Cooper (Jim Parsons), Leonard Hofstadter (Johnny Galecki), as well as Penny (Kaley Cuoco), Howard Wolowitz (Simon Helberg), and Rajesh “Raj” Koothrappali (Kunal Nayyar).

However, a year prior, TBBT debuted with an unaired original pilot that only featured Sheldon and Leonard’s characters from those listed above. The episode also featured Amanda Walsh portraying a character named Katie, while Iris Bahr played a woman named Gilda.