I cannot, yet I must. How do you calculate that? At what point on the graph do must and cannot meet? Yet I must, but I cannot.

— Ro Man The Robot Monster (George Barrows)

13 seconds sound clip from the Robot Monster (1953) movie soundboard.

You can hear this line at 01:02:53.645 in the Blu-ray version of the movie.

Quote context

[...]

- Yes, to be like the Hu-Man: to laugh, feel, want. Why are these things not in the plan?

- You are an extension of the Ro-Men, and a Ro-Man you will remain.

- Now I set you into motion.

- One, destroy the girl. Two, destroy the family.

- Fail, and I will destroy you.

- I cannot, yet I must. How do you calculate that? At what point on the graph do must and cannot meet? Yet I must, but I cannot.

- Attention! Attention, Extension XJ-2!

- Speak, Great Guidance!

- Why have you not killed the girl?

- I must, but I cannot!

- Here I am, Ro-Man!

[...]