The typical horror film plot involves the protagonist avoiding (trying to escape from) the monster (the antagonist). The horror protagonist is almost always reactive (even if the storyline incorporates an arc for the protagonist). The same is true of many thrillers. In thrillers, the protagonist’s arc often entails a move from passive / reactive to active (Marathon Man, e.g.), usually during Act 2. Act 3 becomes the testing of the protagonist’s newfound initiative.

(P. S. the protagonist “trying to figure out the antagonist” is often the struggle of the protagonist to come to terms with her own dark side in order to avoid dominated by the dark side, i.e. to achieve wholeness / reconciliation).