The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
TheNinth
Since: Nov, 2009

I'm sure it was in here somewhere... A conversation takes place, and a new person comes up and joins in just as if they were there all the time, perfectly answering a hanging question. Constantly done in NCIS and Castle.
Edited by Sinus