Our C-ray, the calcinator death ray, cannot penetrate them. They have been made immune through the antibiotic serum which I believe is the same as our formula X-Z-A.
11 seconds sound clip from the Robot Monster (1953) movie soundboard.
You can hear this line at 00:47:59.085 in the Blu-ray version of the movie.
Quote context
[...]
- Have you been playing house?
- Oh, yes!
- Great Guidance, I have discovered the secret of our failure to destroy the remaining Hu-Mans!
- Reduce their counter-power! Eliminate the error!
- Death to Hu-Mans can come by force!
- I will use physical means, Great One. The plan shall be fulfilled.
- The planet Earth has half revolved. You have but a short time to achieve our goal.
[...]