With them are Arthur Dent and Ford Prefect.
4 seconds sound clip from The Hitchhiker's Guide to the Galaxy (1981) - Episode 6 sitcom.
You can hear this line at 00:21:49.385 in the Blu-ray version of the TV Series.
Quote context
[...]
- With them are Arthur Dent and Ford Prefect.
- They too have been traveling widely in distant lands.
- Something is bothering them.
- It is very, very odd. There is one way to find out, of course.
- What, you mean by going to... Yes. All right.
- Yes. I remember you saying how odd you thought it was.
- I find it very easy to believe things.
[...]