Trust your first instincts, “Quantico” fans. Throughout Season 1, everyone has been suspected as the terrorist on the ABC drama. From the beginning, Liam gave fans reason to believe it was him, but the show quickly convinced viewers that it had to be one of the new agents in training. However, episode 21 revealed that it was the assistant director all along, proving that not every clue can be trusted.

Earlier this year, an anonymous tip claimed that the terrorist was someone in Alex’s (Priyanka Chopra) class. That wasn’t just a red herring for viewers. Showrunner Josh Safran explained that the information, which Elias (Rick Cosnett) called in, was meant to distract the characters. “The tip said that it was a member of the class so that everyone would look at Alex,” Safran told TV Guide. “The whole point was to frame Alex. The tip was never the truth because it was Liam making a lie and calling in the tip.”

Safran and the “Quantico” writers considered changing their original plan and making one of the NATs the terrorist, but ultimately, Liam (Josh Hopkins) being the bomber seemed to fit the show’s themes. “We talked about it a lot, but the reality is when you hear the why, it’s more about how this is a cautionary tale of who you could be,” he teased to Entertainment Weekly. “All the secrets we carry with us, if we don’t deal with them, that’s who you could turn into. So we just felt that thematically, that was the story we wanted to tell.”

The reveal came in episode 21 just after Ryan (Jake McLaughlin) realized that Liam had been involved in one too many cases that went wrong. Ryan didn’t seem to suspect him of being a terrorist, just a bad agent. It was Miranda (Aunjanue Ellis) who realized it could be Liam. She thought he was in D.C., so she broke into his house and found all of his surveillance equipment (including cameras inside the FBI offices). Of course, Liam wasn’t actually in D.C. He was in his house and shot his former friend. Fans are left waiting to find out if Miranda survives.

Audiences will also have to wait until the finale to see why Liam turned to the dark side. “All I can say right now is that I knew it was Liam from the very beginning and if you look, it really was clear in every speech that he gave them,” Safran explained. “And the Omaha and the Chicago stuff might have seemed arbitrary a little bit, but it wasn’t, [and] trying to get Alex thrown out and then trying to change his tune there, that’s all dealt with next week, so you’ll see.”

The finale will explain exactly how Liam pulled off this twisted plan, but the majority of the hour will reveal why the agent turned his back on the bureau. The “Quantico” Season 1 finale airs Sunday at 10 p.m. EDT on ABC.