Arcadia as Booker's Seven Basic Plots Analysis: The Quest Plot
Plot Type :
Thomasina thinks that math should be able to describe nature / Bernard is convinced that Byron killed Chater
These two realizations are what set these characters on their paths; much of what they do for the rest of the play is in service of developing these initial lightbulb moments.
Thomasina fills pages upon pages with numbers and graphs / Bernard combs Sidley Park looking for favorable evidence.
Having formed ideas in a flash of insight, the two characters go about the much slower work of developing and supporting their ideas.
Arrival and Frustration
Thomasina lacks the math knowledge to explain her ideas / Bernard finds some evidence, but not enough to be wholly convincing.
Both characters get closer to their goals, only to find that there's something essential missing, which holds them back.
The Final Ordeals
Thomasina dies / Bernard gets the throw-down from Hannah's superior knowledge of dahlia history.
Progress forward is halted for both by insurmountable barriers: death and definite contrary evidence.
Neither Thomasina nor Bernard manages to turn their initial "Eureka!" moments into commonly accepted fact. Their quests fail, but perhaps Hannah's right: it's the quest, not the goal, that's the point.