The hard-to-adapt plot
The 1961 film and the musical both do a lot of Adaptation Expansion (the film on Grey's storyline, the musical on Assol's storyline). However, it is pretty much inevitable. The book has a pretty episodic structure: plot-relevant events in Assol's life (Mary's death, Menners Sr.'s death, the scarlet sails prophecy, and Grey's arrival) are scattered across seventeen years with nothing significant happening in-between, while Grey's backstory is summarized in a single chapter. It works in the book, and it works (for a niche audience) in the surrealist 1982 film. However, if one wants to do a more conventional plot-driven adaptation, tweaking the original plot is absolutely necessary to translate it to the screen or stage.Assol Promoted to Love Interest for Hin Menners
That's a plot element shared by Assol and the musical. Due to the 1982 film's relative obscurity, it's hard to tell if the musical borrowed it or if it's a case of Surprisingly-Similar Stories. But in fact, it's one of the few ways of doing an Adaptation Expansion without veering too far away from the original canon. First, Hin is the only named character in Assol's age range in Kaperna. Second, the canon circumstances already provide the ideal layout for a Rule of Drama-laden love triangle — after the deaths of Mary and Menners Sr., we have a small-scale case of Feuding Families; moreover, if Assol is courted by Hin, it provides a Betty and Veronica conflict for her. In the book and the 1961 film, the chances of the villagers' opinion of her and her family ever changing are minuscule, but in the 1982 film and the musical, she has a choice of accepting Hin and thus not just gaining money and security but also getting into the villagers' good graces — out of sheer pragmatism, they'd refrain from insulting the innkeeper's wife at least to her face.This way, Assol's romance with Grey can clearly be shown as her own choice and not just something that she passively accepts. In the book, the internal monologues and narration help us see the development of the romance, but as it's hard to translate to a visual medium, a love triangle with Hin can provide both drama in general and Show, Don't Tell for Assol's romantic arc.
