Why, it's too simple. I lift the iron grill slip out a trapdoor. The colored gas conceals my actions.
10 seconds sound clip from Batman (1966) - Zelda the Great (S1E9) TV Series.
You can hear this line at 00:14:07 in the Blu-ray version of the episode.
Quote context
[...]
- Of course, I told you. It's unbreakable.
- Please, come up on the stage. Examine more closely.
- Step inside. The hinged wall is closed and padlocked by member of the audience.
- From the floor grill is pouring a deadly-colored gas.
- The audience is screaming for you to escape. How do you do it?
- Oh, the grill's electrified.
- Oh, it's wonderful. Oh, wonderful.
- Now, tell me... What's the secret of my getting out?
[...]