Lt. Columbo and Paul Hanlon in “Unfinished Business”

Lt. Columbo

You know, I listened to this thing I can't tell ya how many times, over and over again, figuring maybe I'd hear something that shouldn't be there, some sound that shouldn't be there, an ambulance, a fire truck, like you were in a phone booth, something...

Paul Hanlon

[impatiently] But you didn't because it isn't there. I made the call from this booth, from that phone.

Lt. Columbo

Then it suddenly occurred to me. I had it backwards. Maybe there was a sound that should be there and wasn't.