- Perhaps we are both going mad.
- Nice day for it. Sun.
- Sea.

7 seconds sound clip from The Hitchhiker's Guide to the Galaxy (1981) - Episode 2 sitcom.

You can hear this line at 00:14:49.606 in the Blu-ray version of the TV Series.

Quote context

[...]

- See, I told you I'd think of something.

- Well, sure.

- Great idea of mine.

- Find a passing spaceship, get rescued by it.

- Oh, come on. The chances against it were astronomical.

- Don't knock it, it worked.

- Where the hell are we?

- Well, I hardly like to say this, but it looks like the seafront at Southend.

- God. I'm relieved to hear you say that.

- Why?

- I thought I must be going mad.

- Perhaps you are. Perhaps you only thought I said that.

- Well, did you, or didn't you?

- I think so.

- Perhaps we are both going mad.

- Nice day for it. Sun.

- Sea.

- You know, if this is Southend, there's something very odd about it.

- What, do you mean the way the sea stays steady as a rock, and the buildings keep washing up and down?

- Yeah.

- I thought that was odd.

- 2 to the power of 700000 to 7 against, and falling.

- What's that?

- Sounded like a measurement of probability.

[...]