Special thanks to Clarius for her post which I've copied here.
Slightly naive perhaps but here's the BUT/THEREFORE in context of the eight point story arc.
P is living their life, doing their thing, existing in STATIS BUT something happens to TRIGGER them out of their reverie THEREFORE they go on a QUEST BUT along the way/when they get there they get a SURPRISE and THEREFORE they have to make a CHOICE BUT this decision brings them into CONFLICT with someone/thing THEREFORE they suffer a REVERSAL of fortune BUT are able to overcome this to reach a satisfactory RESOLUTION.
But good story telling relies upon these elements in an order which is linear though not necessarily sequential.
Luke is living on Tatooine(STASIS) BUT then his Uncle buys two droids who reveal they have a mission (TRIGGER) THEREFORE Luke goes to look for the mysterious Obi-Wan Kenobi(QUEST) who tells(ish) him about his father(SURPRISE) BUT this isn't enough to jolt Luke out of his STATIS and he opts to go back home BUT discovers that the Empire have murdered his Uncle/Aunt(TRIGGER) and THEREFORE Luke, having nothing to stay for, opts(CHOICE) to help Ben deliver the Death Star plans(QUEST) BUT first they have to find a ship(QUEST) and, having found one, THEREFORE off they go BUT find that their destination , the planet Alderaan, is missing(SURPRISE) so THEREFORE they decide (CHOICE) to investigate a nearby moon BUT it's the Death Star...
^ I ran out of steam trying to summarise Star Wars because it quickly became apparent that the plot is not a linear eight point arc but contains a mixture of all the essential elements - the eight points - all of which are interspersed with either a BUT or THEREFORE.
