ON ACTING: Character 'Arc'
An arc is the beginning, middle and end progression of character or inner emotional change.
A well acted scene is like an inner detective story: as ‘the case’, the plot, moves toward resolution, the audience (and often inadvertently, the character) discovers the emotional content of the character’s inner ‘story’. Personal emotional truth is increasingly revealed. The character’s inner emotional ‘plot’ unfolds in a manner that mirrors the unfolding of the character’s outer factual plot.
Thus, in every good scene, unfolding inner and outer truth arcs has, by the end of the scene, melded into one revealing culminating climax.