(Carter and Zelenka are trapped in one of the city's transporter chambers)
Carter: (Sighs) We could really use one of your pigeons around now.
Zelenka: Well, they're not for eating!
Carter: Oh, no, I meant, you know, to get help.
(Zelenka looks confused)
Carter: Like homing pigeons, you attach a little SOS note to their feet and... (Gestures letting a pigeon go)
Zelenka: But there's no window in here?
Carter: I know, I was just...
(Carter looks away)