“Got a secret, can you keep it?” Those are the lyrics that start off the theme to the mystery series Pretty Little Liars. The song, titled “Secret” by the Pierces, plays while the four Liars (played by Lucy Hale, Ashley Benson, Troian Bellisario and Shay Mitchell) are shown around a casket and hold their fingers in front of their mouths for the iconic “shhh,” with Aria (Hale) specifically getting a close-up shot (with the well-known off-center “shhh”) to conclude. In the second half of season six, Sasha Pieterse’s Alison was added for the intro. 

Benson discovered the tune and showed it to her castmembers while they were shooting the pilot in Vancouver. 

“Randomly, I was on Spotify, and I was on a playlist, and somehow that song came into my shuffle,” Benson told The Hollywood Reporter in an interview tied to PLL’s 15th anniversary. “I was like, ‘That’s so weird.’ And I kind of just went past it, and then I put it on again, and I listened to the words. At the time, we were all reading the books. So I was like, ‘Oh my God, this is a crazy song. This is literally what the show’s about!’”

Halfway through shooting the pilot, Benson pitched the song to the show’s creator, Marlene King, as she was convinced that the track had to be the theme music and recalled telling King, “I just don’t see any other song being the song for the show.”