The cast reveals how they keep all the spoilers from leaking.
Shonda Rhimes, the producer behind Grey's Anatomy, How to Get Away With Murder and Scandal, is known for creating shocking moments on her shows, but how have none of those surprising twists and turns leaked?
ET caught up with the How to Get Away with Murder cast on the red carpet of the Entertainment Weekly SAG Awards pre-party, where they revealed the great lengths the show goes to maintain its mystery.
Karla Souza (Laurel) explained that their call sheets are water marked. "And after you finish doing one scene, you have to shred it," she said. "It feels like you're doing a top secret CIA intervention somewhere."
The high security gets even more intense for the most coveted episode this season. The two-hour season finale will take place earlier than most shows -- airing on Feb. 26 at 9 p.m. ET -- because HTGAWM received a limited order from ABC for 15 total episodes in season 1.
But in order to keep the highly anticipated finale a secret, Souza said they weren’t allowed to talk about it with anyone else and that the set was completely closed to the point that even her own mother couldn’t visit her on set.
NEWS: On Set with the Cast of 'How to Get Away With Murder'
For the finale's scripts, Matt McGorry (Asher) revealed that they were given hard copies because emails can't be trusted. The scripts have to be signed out, and the cast has to physically receive them. "They can’t be left at our door step," he said.
The strict protocol has Katie Findlay (Rebecca) joking about a "Shondaland FBI van" outside her house that’s disguised as a flower van. She described the paranoia, "[It's] just waiting in case I say anything off hand."
WATCH: 'How to Get Away With Murder' Sneak Peek: Hell Hath No Fury Like an Annalise Scorned!
While there's a tight lid on the season 1 finale, there's no word on the show’s fate. "We haven't officially been told we're coming back," McGorry said of ABC's decision on whether to pick up the Golden Globe-nominated show for a second season.
Catch a new episode of HTGAWM tonight, and check out the video above for secrets from the cast!
Follow Rosalyn on Twitter: @RosalynOsh