Oh, incidentally... You're the only one who knows who we are.
6 seconds sound clip from the Bullets or Ballots (1939) classic radio play.
You can hear this line at 00:47:55 in the radio play.
Quote context
[...]
- Yes... you have given us quite a bit of revenue.
- You're satisfied, gentlemen?
- Thanks. You're not making any mistake.
- Oh, incidentally... You're the only one who knows who we are.
- Yeah? Well, I already arranged to collect them.
- Would it be all right if I get here 10?
[...]