Miles O’Brien: Four weeks? Are you telling me I’ve been hanging around a Changeling for over a month?

Julian Bashir: And you never even suspected it wasn’t me?

Miles O’Brien: No. And the worst part is, the clues were right in front of me.

Julian Bashir: What clues?

Miles O’Brien: Well, for one thing, he… was a lot easier to get along with.

Star Trek: Deep Space Nine, Season 5: Episode 15 – “By Inferno’s Light”