In fact, they had reached a most advanced stage. They were becoming dangerous.
7 seconds sound clip from the Frankenstein (1931) movie soundboard.
You can hear this line at 00:12:29 in the Blu-ray version of the movie.
Quote context
[...]
- But, Elizabeth, you can't do that!
- I must! I'll be ready in a minute.
- Herr Frankenstein is a most brilliant young man, yet so erratic, he troubles me.
- Why has he left the university? He was doing so well, and he seemed so happy with his work.
- In fact, they had reached a most advanced stage. They were becoming dangerous.
- Herr Frankenstein is greatly changed.
- You mean, changed as a result of his work?
- His insane ambition to create life.
- How? How? Please tell us everything, whatever it is.
[...]