The passengers on the plane were a 'captive audience'. [=the passengers on the plane could not leave and had to listen to what was being said]
Enemy forces took/held them 'captive'. [=took or kept them as prisoners]
The 'captive' soldiers planned their escape.
(..) slip past our nets. We are no spies. We track a party of Uruk-hai westward across the plain. They have taken two of our friends captive. The Uruks are destroyed. We slaughtered them during the night. But there were two Hobbits. Did you see two Hobbits with them? They would be small. (..)2002 The Lord of the Rings: The Two Towers