[1] Colleen McCullough, author of The Thorn Birds, evidently used The Blue Castle as the basis of her novel The Ladies of Missalonghi—subconsciously, as she alleged—to the point of provoking accusations of plagiarism.

Believing she has very little time left to live, she decides to break free from the oppressive constraints, expectations, and obligations her ever-judging family has laid on her since birth.

Valancy then scandalizes the clan even more by moving out of her mother's house and taking a position as a housekeeper for her very ill childhood friend Cissy Gay and her father, who is a master carpenter and notorious town drunk named Roaring Abel.

They build a contented life together, though he forbids her from ever entering a certain room which she dubs 'Bluebeard's Chamber', claiming that he could have multiple wives strung up on the walls by their hair.

Barney and Valancy share wonderful conversations and take long walks on the mainland, she often quoting from books by John Foster, which he abhors and refuses to listen to.

Valancy also takes the time to exorcise old demons, building a large sand pile to make up for one that her cousin Olive had stolen from her when they were in grade school.

Also, while Valancy is collecting moss and flowers to decorate their cabin, she comes upon Allan Tierney, a celebrated painter of beautiful women, who, when he sees her, hastens to find Barney and asks to paint her portrait, which he declines.

She writes the note, explaining the mix-up behind her diagnosis and asking for a divorce, knowing now that he can afford it and leaves behind the necklace, which she had earlier thought an expensive imitation.

Valancy returns home despondent and reveals to her family that Barney is the son of famous and wealthy Dr. Redfern, as well as the noted literary figure John Foster.

Barney's absence after the train incident was due to the stunned realization that he had grown to love her so much, he would not want to live without her and so he was contemplating contacting his father for the first time in a decade to ask for money to pay for expensive medical treatments that could somehow heal her.

At first she refuses, believing that he is only asking out of pity, but when he becomes angry, thinking she is ashamed of his father's patent medicine business just like his ex-girlfriend was, she realizes he does love her and agrees to return.

In a post-credit-like page, Olive is writing to her fiancee, Cecil Bruce, telling him about Valancy marrying Barney and how they discovered he was a millionaire in his own right, and how now every single relative is positively fawning over the couple.

In an almost jealous diatribe, she wonders why some people can make their entire lives an utter mess with their adventures and yet end up married to a rich person, and she says that if this is what happens when someone runs away and flouts family expectations, then what is the use in behaving?