The Third-Act Lull: The exact moment where a movie which has had a careful escalation of the plot, leading up to an exciting climactic moment where the action reaches a cresendo... except the problem is they're only two-thirds through the movie, so the carefully built escalation suddenly flat-lines for a while and they have to bring it all back up again for a second finale.
Example: the original Star Wars maintains a carefully built escalation of events, which is released when the princess is saved and the Falcon escapes the Death Star..... whereupon they go into an extended sequence on Yavin which feels positively low-key compared to the entire movie up till that point, before again rising to a second exciting climax with the Death Star run itself.